assignment operator for string in c

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7 Assignment Expressions

As a general concept in programming, an assignment is a construct that stores a new value into a place where values can be stored—for instance, in a variable. Such places are called lvalues (see Lvalues ) because they are locations that hold a value.

An assignment in C is an expression because it has a value; we call it an assignment expression . A simple assignment looks like

We say it assigns the value of the expression value-to-store to the location lvalue , or that it stores value-to-store there. You can think of the “l” in “lvalue” as standing for “left,” since that’s what you put on the left side of the assignment operator.

However, that’s not the only way to use an lvalue, and not all lvalues can be assigned to. To use the lvalue in the left side of an assignment, it has to be modifiable . In C, that means it was not declared with the type qualifier const (see const ).

The value of the assignment expression is that of lvalue after the new value is stored in it. This means you can use an assignment inside other expressions. Assignment operators are right-associative so that

is equivalent to

This is the only useful way for them to associate; the other way,

would be invalid since an assignment expression such as x = y is not valid as an lvalue.

Warning: Write parentheses around an assignment if you nest it inside another expression, unless that is a conditional expression, or comma-separated series, or another assignment.

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In C programming, a string is a sequence of characters terminated with a null character \0 . For example:

When the compiler encounters a sequence of characters enclosed in the double quotation marks, it appends a null character \0 at the end by default.

• How to declare a string?

Here's how you can declare strings:

Here, we have declared a string of 5 characters.

• How to initialize strings?

You can initialize strings in a number of ways.

Let's take another example:

Here, we are trying to assign 6 characters (the last character is '\0' ) to a char array having 5 characters. This is bad and you should never do this.

Assigning Values to Strings

Arrays and strings are second-class citizens in C; they do not support the assignment operator once it is declared. For example,

Note: Use the strcpy() function to copy the string instead.

Read String from the user

You can use the scanf() function to read a string.

The scanf() function reads the sequence of characters until it encounters whitespace (space, newline, tab, etc.).

Example 1: scanf() to read a string

Even though Dennis Ritchie was entered in the above program, only "Dennis" was stored in the name string. It's because there was a space after Dennis .

Also notice that we have used the code name instead of &name with scanf() .

This is because name is a char array, and we know that array names decay to pointers in C.

Thus, the  name  in  scanf() already points to the address of the first element in the string, which is why we don't need to use & .

How to read a line of text?

You can use the fgets() function to read a line of string. And, you can use puts() to display the string.

Example 2: fgets() and puts()

Here, we have used fgets() function to read a string from the user.

fgets(name, sizeof(name), stdlin); // read string

The sizeof(name) results to 30. Hence, we can take a maximum of 30 characters as input which is the size of the  name string.

To print the string, we have used puts(name); .

Note: The gets() function can also be to take input from the user. However, it is removed from the C standard. It's because gets() allows you to input any length of characters. Hence, there might be a buffer overflow.

Passing Strings to Functions

Strings can be passed to a function in a similar way as arrays. Learn more about passing arrays to a function .

Example 3: Passing string to a Function

Strings and pointers.

Similar like arrays, string names are "decayed" to pointers. Hence, you can use pointers to manipulate elements of the string. We recommended you to check C Arrays and Pointers before you check this example.

Example 4: Strings and Pointers

Commonly used string functions.

• strlen() - calculates the length of a string
• strcpy() - copies a string to another
• strcmp() - compares two strings
• strcat() - concatenates two strings

Table of Contents

• Read and Write String: gets() and puts()
• Passing strings to a function
• Strings and pointers
• Commonly used string functions

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21.12 — Overloading the assignment operator

The copy assignment operator (operator=) is used to copy values from one object to another already existing object .

Related content

As of C++11, C++ also supports “Move assignment”. We discuss move assignment in lesson 22.3 -- Move constructors and move assignment .

Copy assignment vs Copy constructor

The purpose of the copy constructor and the copy assignment operator are almost equivalent -- both copy one object to another. However, the copy constructor initializes new objects, whereas the assignment operator replaces the contents of existing objects.

The difference between the copy constructor and the copy assignment operator causes a lot of confusion for new programmers, but it’s really not all that difficult. Summarizing:

• If a new object has to be created before the copying can occur, the copy constructor is used (note: this includes passing or returning objects by value).
• If a new object does not have to be created before the copying can occur, the assignment operator is used.

Overloading the assignment operator

Overloading the copy assignment operator (operator=) is fairly straightforward, with one specific caveat that we’ll get to. The copy assignment operator must be overloaded as a member function.

This prints:

This should all be pretty straightforward by now. Our overloaded operator= returns *this, so that we can chain multiple assignments together:

Issues due to self-assignment

Here’s where things start to get a little more interesting. C++ allows self-assignment:

This will call f1.operator=(f1), and under the simplistic implementation above, all of the members will be assigned to themselves. In this particular example, the self-assignment causes each member to be assigned to itself, which has no overall impact, other than wasting time. In most cases, a self-assignment doesn’t need to do anything at all!

However, in cases where an assignment operator needs to dynamically assign memory, self-assignment can actually be dangerous:

First, run the program as it is. You’ll see that the program prints “Alex” as it should.

Now run the following program:

You’ll probably get garbage output. What happened?

Consider what happens in the overloaded operator= when the implicit object AND the passed in parameter (str) are both variable alex. In this case, m_data is the same as str.m_data. The first thing that happens is that the function checks to see if the implicit object already has a string. If so, it needs to delete it, so we don’t end up with a memory leak. In this case, m_data is allocated, so the function deletes m_data. But because str is the same as *this, the string that we wanted to copy has been deleted and m_data (and str.m_data) are dangling.

Later on, we allocate new memory to m_data (and str.m_data). So when we subsequently copy the data from str.m_data into m_data, we’re copying garbage, because str.m_data was never initialized.

Detecting and handling self-assignment

Fortunately, we can detect when self-assignment occurs. Here’s an updated implementation of our overloaded operator= for the MyString class:

By checking if the address of our implicit object is the same as the address of the object being passed in as a parameter, we can have our assignment operator just return immediately without doing any other work.

Because this is just a pointer comparison, it should be fast, and does not require operator== to be overloaded.

When not to handle self-assignment

Typically the self-assignment check is skipped for copy constructors. Because the object being copy constructed is newly created, the only case where the newly created object can be equal to the object being copied is when you try to initialize a newly defined object with itself:

In such cases, your compiler should warn you that c is an uninitialized variable.

Second, the self-assignment check may be omitted in classes that can naturally handle self-assignment. Consider this Fraction class assignment operator that has a self-assignment guard:

If the self-assignment guard did not exist, this function would still operate correctly during a self-assignment (because all of the operations done by the function can handle self-assignment properly).

Because self-assignment is a rare event, some prominent C++ gurus recommend omitting the self-assignment guard even in classes that would benefit from it. We do not recommend this, as we believe it’s a better practice to code defensively and then selectively optimize later.

The copy and swap idiom

A better way to handle self-assignment issues is via what’s called the copy and swap idiom. There’s a great writeup of how this idiom works on Stack Overflow .

The implicit copy assignment operator

Unlike other operators, the compiler will provide an implicit public copy assignment operator for your class if you do not provide a user-defined one. This assignment operator does memberwise assignment (which is essentially the same as the memberwise initialization that default copy constructors do).

Just like other constructors and operators, you can prevent assignments from being made by making your copy assignment operator private or using the delete keyword:

Note that if your class has const members, the compiler will instead define the implicit operator= as deleted. This is because const members can’t be assigned, so the compiler will assume your class should not be assignable.

If you want a class with const members to be assignable (for all members that aren’t const), you will need to explicitly overload operator= and manually assign each non-const member.

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Assignment Operators In C++

In C++, the assignment operator forms the backbone of many algorithms and computational processes by performing a simple operation like assigning a value to a variable. It is denoted by equal sign ( = ) and provides one of the most basic operations in any programming language that is used to assign some value to the variables in C++ or in other words, it is used to store some kind of information.

The right-hand side value will be assigned to the variable on the left-hand side. The variable and the value should be of the same data type.

The value can be a literal or another variable of the same data type.

Compound Assignment Operators

In C++, the assignment operator can be combined into a single operator with some other operators to perform a combination of two operations in one single statement. These operators are called Compound Assignment Operators. There are 10 compound assignment operators in C++:

• Addition Assignment Operator ( += )
• Subtraction Assignment Operator ( -= )
• Multiplication Assignment Operator ( *= )
• Division Assignment Operator ( /= )
• Modulus Assignment Operator ( %= )
• Bitwise AND Assignment Operator ( &= )
• Bitwise OR Assignment Operator ( |= )
• Bitwise XOR Assignment Operator ( ^= )
• Left Shift Assignment Operator ( <<= )
• Right Shift Assignment Operator ( >>= )

Lets see each of them in detail.

1. Addition Assignment Operator (+=)

In C++, the addition assignment operator (+=) combines the addition operation with the variable assignment allowing you to increment the value of variable by a specified expression in a concise and efficient way.

This above expression is equivalent to the expression:

2. Subtraction Assignment Operator (-=)

The subtraction assignment operator (-=) in C++ enables you to update the value of the variable by subtracting another value from it. This operator is especially useful when you need to perform subtraction and store the result back in the same variable.

3. Multiplication Assignment Operator (*=)

In C++, the multiplication assignment operator (*=) is used to update the value of the variable by multiplying it with another value.

4. Division Assignment Operator (/=)

The division assignment operator divides the variable on the left by the value on the right and assigns the result to the variable on the left.

5. Modulus Assignment Operator (%=)

The modulus assignment operator calculates the remainder when the variable on the left is divided by the value or variable on the right and assigns the result to the variable on the left.

6. Bitwise AND Assignment Operator (&=)

This operator performs a bitwise AND between the variable on the left and the value on the right and assigns the result to the variable on the left.

7. Bitwise OR Assignment Operator (|=)

The bitwise OR assignment operator performs a bitwise OR between the variable on the left and the value or variable on the right and assigns the result to the variable on the left.

8. Bitwise XOR Assignment Operator (^=)

The bitwise XOR assignment operator performs a bitwise XOR between the variable on the left and the value or variable on the right and assigns the result to the variable on the left.

9. Left Shift Assignment Operator (<<=)

The left shift assignment operator shifts the bits of the variable on the left to left by the number of positions specified on the right and assigns the result to the variable on the left.

10. Right Shift Assignment Operator (>>=)

The right shift assignment operator shifts the bits of the variable on the left to the right by a number of positions specified on the right and assigns the result to the variable on the left.

Also, it is important to note that all of the above operators can be overloaded for custom operations with user-defined data types to perform the operations we want.

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Assignment operator in c.

Last Updated on June 23, 2023 by Prepbytes

This type of operator is employed for transforming and assigning values to variables within an operation. In an assignment operation, the right side represents a value, while the left side corresponds to a variable. It is essential that the value on the right side has the same data type as the variable on the left side. If this requirement is not fulfilled, the compiler will issue an error.

What is Assignment Operator in C language?

In C, the assignment operator serves the purpose of assigning a value to a variable. It is denoted by the equals sign (=) and plays a vital role in storing data within variables for further utilization in code. When using the assignment operator, the value present on the right-hand side is assigned to the variable on the left-hand side. This fundamental operation allows developers to store and manipulate data effectively throughout their programs.

Example of Assignment Operator in C

For example, consider the following line of code:

Types of Assignment Operators in C

Here is a list of the assignment operators that you can find in the C language:

Simple assignment operator (=): This is the basic assignment operator, which assigns the value on the right-hand side to the variable on the left-hand side.

Addition assignment operator (+=): This operator adds the value on the right-hand side to the variable on the left-hand side and assigns the result back to the variable.

x += 3; // Equivalent to x = x + 3; (adds 3 to the current value of "x" and assigns the result back to "x")

Subtraction assignment operator (-=): This operator subtracts the value on the right-hand side from the variable on the left-hand side and assigns the result back to the variable.

x -= 4; // Equivalent to x = x – 4; (subtracts 4 from the current value of "x" and assigns the result back to "x")

* Multiplication assignment operator ( =):** This operator multiplies the value on the right-hand side with the variable on the left-hand side and assigns the result back to the variable.

x = 2; // Equivalent to x = x 2; (multiplies the current value of "x" by 2 and assigns the result back to "x")

Division assignment operator (/=): This operator divides the variable on the left-hand side by the value on the right-hand side and assigns the result back to the variable.

x /= 2; // Equivalent to x = x / 2; (divides the current value of "x" by 2 and assigns the result back to "x")

Bitwise AND assignment (&=): The bitwise AND assignment operator "&=" performs a bitwise AND operation between the value on the left-hand side and the value on the right-hand side. It then assigns the result back to the left-hand side variable.

x &= 3; // Binary: 0011 // After bitwise AND assignment: x = 1 (Binary: 0001)

Bitwise OR assignment (|=): The bitwise OR assignment operator "|=" performs a bitwise OR operation between the value on the left-hand side and the value on the right-hand side. It then assigns the result back to the left-hand side variable.

x |= 3; // Binary: 0011 // After bitwise OR assignment: x = 7 (Binary: 0111)

Bitwise XOR assignment (^=): The bitwise XOR assignment operator "^=" performs a bitwise XOR operation between the value on the left-hand side and the value on the right-hand side. It then assigns the result back to the left-hand side variable.

x ^= 3; // Binary: 0011 // After bitwise XOR assignment: x = 6 (Binary: 0110)

Left shift assignment (<<=): The left shift assignment operator "<<=" shifts the bits of the value on the left-hand side to the left by the number of positions specified by the value on the right-hand side. It then assigns the result back to the left-hand side variable.

x <<= 2; // Binary: 010100 (Shifted left by 2 positions) // After left shift assignment: x = 20 (Binary: 10100)

Right shift assignment (>>=): The right shift assignment operator ">>=" shifts the bits of the value on the left-hand side to the right by the number of positions specified by the value on the right-hand side. It then assigns the result back to the left-hand side variable.

x >>= 2; // Binary: 101 (Shifted right by 2 positions) // After right shift assignment: x = 5 (Binary: 101)

Conclusion The assignment operator in C, denoted by the equals sign (=), is used to assign a value to a variable. It is a fundamental operation that allows programmers to store data in variables for further use in their code. In addition to the simple assignment operator, C provides compound assignment operators that combine arithmetic or bitwise operations with assignment, allowing for concise and efficient code.

FAQs related to Assignment Operator in C

Q1. Can I assign a value of one data type to a variable of another data type? In most cases, assigning a value of one data type to a variable of another data type will result in a warning or error from the compiler. It is generally recommended to assign values of compatible data types to variables.

Q2. What is the difference between the assignment operator (=) and the comparison operator (==)? The assignment operator (=) is used to assign a value to a variable, while the comparison operator (==) is used to check if two values are equal. It is important not to confuse these two operators.

Q3. Can I use multiple assignment operators in a single statement? No, it is not possible to use multiple assignment operators in a single statement. Each assignment operator should be used separately for assigning values to different variables.

Q4. Are there any limitations on the right-hand side value of the assignment operator? The right-hand side value of the assignment operator should be compatible with the data type of the left-hand side variable. If the data types are not compatible, it may lead to unexpected behavior or compiler errors.

Q5. Can I assign the result of an expression to a variable using the assignment operator? Yes, it is possible to assign the result of an expression to a variable using the assignment operator. For example, x = y + z; assigns the sum of y and z to the variable x.

Q6. What happens if I assign a value to an uninitialized variable? Assigning a value to an uninitialized variable will initialize it with the assigned value. However, it is considered good practice to explicitly initialize variables before using them to avoid potential bugs or unintended behavior.

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Assignment operators.

Assignment and compound assignment operators are binary operators that modify the variable to their left using the value to their right.

[ edit ] Simple assignment

The simple assignment operator expressions have the form

Assignment performs implicit conversion from the value of rhs to the type of lhs and then replaces the value in the object designated by lhs with the converted value of rhs .

Assignment also returns the same value as what was stored in lhs (so that expressions such as a = b = c are possible). The value category of the assignment operator is non-lvalue (so that expressions such as ( a = b ) = c are invalid).

rhs and lhs must satisfy one of the following:

• both lhs and rhs have compatible struct or union type, or..
• rhs must be implicitly convertible to lhs , which implies
• both lhs and rhs have arithmetic types , in which case lhs may be volatile -qualified or atomic (since C11)
• both lhs and rhs have pointer to compatible (ignoring qualifiers) types, or one of the pointers is a pointer to void, and the conversion would not add qualifiers to the pointed-to type. lhs may be volatile or restrict (since C99) -qualified or atomic (since C11) .
• lhs is a (possibly qualified or atomic (since C11) ) pointer and rhs is a null pointer constant such as NULL or a nullptr_t value (since C23)

[ edit ] Notes

If rhs and lhs overlap in memory (e.g. they are members of the same union), the behavior is undefined unless the overlap is exact and the types are compatible .

Although arrays are not assignable, an array wrapped in a struct is assignable to another object of the same (or compatible) struct type.

The side effect of updating lhs is sequenced after the value computations, but not the side effects of lhs and rhs themselves and the evaluations of the operands are, as usual, unsequenced relative to each other (so the expressions such as i = ++ i ; are undefined)

Assignment strips extra range and precision from floating-point expressions (see FLT_EVAL_METHOD ).

In C++, assignment operators are lvalue expressions, not so in C.

[ edit ] Compound assignment

The compound assignment operator expressions have the form

The expression lhs @= rhs is exactly the same as lhs = lhs @ ( rhs ) , except that lhs is evaluated only once.

[ edit ] References

• C17 standard (ISO/IEC 9899:2018):
• 6.5.16 Assignment operators (p: 72-73)
• C11 standard (ISO/IEC 9899:2011):
• 6.5.16 Assignment operators (p: 101-104)
• C99 standard (ISO/IEC 9899:1999):
• 6.5.16 Assignment operators (p: 91-93)
• C89/C90 standard (ISO/IEC 9899:1990):
• 3.3.16 Assignment operators

[ edit ] See Also

Operator precedence

[ edit ] See also

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C Programming Tutorial

• Assignment Operator in C

Last updated on July 27, 2020

We have already used the assignment operator ( = ) several times before. Let's discuss it here in detail. The assignment operator ( = ) is used to assign a value to the variable. Its general format is as follows:

The operand on the left side of the assignment operator must be a variable and operand on the right-hand side must be a constant, variable or expression. Here are some examples:

The precedence of the assignment operator is lower than all the operators we have discussed so far and it associates from right to left.

We can also assign the same value to multiple variables at once.

here x , y and z are initialized to 100 .

Since the associativity of the assignment operator ( = ) is from right to left. The above expression is equivalent to the following:

Note that expressions like:

are called assignment expression. If we put a semicolon( ; ) at the end of the expression like this:

then the assignment expression becomes assignment statement.

Compound Assignment Operator #

Assignment operations that use the old value of a variable to compute its new value are called Compound Assignment.

Consider the following two statements:

Here the second statement adds 5 to the existing value of x . This value is then assigned back to x . Now, the new value of x is 105 .

To handle such operations more succinctly, C provides a special operator called Compound Assignment operator.

The general format of compound assignment operator is as follows:

where op can be any of the arithmetic operators ( + , - , * , / , % ). The above statement is functionally equivalent to the following:

Note : In addition to arithmetic operators, op can also be >> (right shift), << (left shift), | (Bitwise OR), & (Bitwise AND), ^ (Bitwise XOR). We haven't discussed these operators yet.

After evaluating the expression, the op operator is then applied to the result of the expression and the current value of the variable (on the RHS). The result of this operation is then assigned back to the variable (on the LHS). Let's take some examples: The statement:

is equivalent to x = x + 5; or x = x + (5); .

Similarly, the statement:

is equivalent to x = x * 2; or x = x * (2); .

Since, expression on the right side of op operator is evaluated first, the statement:

is equivalent to x = x * (y + 1) .

The precedence of compound assignment operators are same and they associate from right to left (see the precedence table ).

The following table lists some Compound assignment operators:

The following program demonstrates Compound assignment operators in action:

Expected Output:

Load Comments

• Intro to C Programming
• Installing Code Blocks
• Creating and Running The First C Program
• Basic Elements of a C Program
• Keywords and Identifiers
• Data Types in C
• Constants in C
• Variables in C
• Input and Output in C
• Formatted Input and Output in C
• Arithmetic Operators in C
• Operator Precedence and Associativity in C
• Increment and Decrement Operators in C
• Relational Operators in C
• Logical Operators in C
• Conditional Operator, Comma operator and sizeof() operator in C
• Implicit Type Conversion in C
• Explicit Type Conversion in C
• if-else statements in C
• The while loop in C
• The do while loop in C
• The for loop in C
• The Infinite Loop in C
• The break and continue statement in C
• The Switch statement in C
• Function basics in C
• The return statement in C
• Actual and Formal arguments in C
• Local, Global and Static variables in C
• Recursive Function in C
• One dimensional Array in C
• One Dimensional Array and Function in C
• Two Dimensional Array in C
• Pointer Basics in C
• Pointer Arithmetic in C
• Pointers and 1-D arrays
• Pointers and 2-D arrays
• Call by Value and Call by Reference in C
• Returning more than one value from function in C
• Returning a Pointer from a Function in C
• Passing 1-D Array to a Function in C
• Passing 2-D Array to a Function in C
• Array of Pointers in C
• Void Pointers in C
• The malloc() Function in C
• The calloc() Function in C
• The realloc() Function in C
• String Basics in C
• The strlen() Function in C
• The strcmp() Function in C
• The strcpy() Function in C
• The strcat() Function in C
• Character Array and Character Pointer in C
• Array of Strings in C
• Array of Pointers to Strings in C
• The sprintf() Function in C
• The sscanf() Function in C
• Structure Basics in C
• Array of Structures in C
• Array as Member of Structure in C
• Nested Structures in C
• Pointer to a Structure in C
• Pointers as Structure Member in C
• Structures and Functions in C
• Union Basics in C
• typedef statement in C
• Basics of File Handling in C
• fputc() Function in C
• fgetc() Function in C
• fputs() Function in C
• fgets() Function in C
• fprintf() Function in C
• fscanf() Function in C
• fwrite() Function in C
• fread() Function in C

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Assignment Operators in C

In C, the assignment operator stores a certain value in an already declared variable. A variable in C can be assigned the value in the form of a literal, another variable or an expression. The value to be assigned forms the right hand operand, whereas the variable to be assigned should be the operand to the left of = symbol, which is defined as a simple assignment operator in C. In addition, C has several augmented assignment operators.

The following table lists the assignment operators supported by the C language −

Simple assignment operator (=)

The = operator is the most frequently used operator in C. As per ANSI C standard, all the variables must be declared in the beginning. Variable declaration after the first processing statement is not allowed. You can declare a variable to be assigned a value later in the code, or you can initialize it at the time of declaration.

You can use a literal, another variable or an expression in the assignment statement.

Once a variable of a certain type is declared, it cannot be assigned a value of any other type. In such a case the C compiler reports a type mismatch error.

In C, the expressions that refer to a memory location are called "lvalue" expressions. A lvalue may appear as either the left-hand or right-hand side of an assignment.

On the other hand, the term rvalue refers to a data value that is stored at some address in memory. A rvalue is an expression that cannot have a value assigned to it which means an rvalue may appear on the right-hand side but not on the left-hand side of an assignment.

Variables are lvalues and so they may appear on the left-hand side of an assignment. Numeric literals are rvalues and so they may not be assigned and cannot appear on the left-hand side. Take a look at the following valid and invalid statements −

Augmented assignment operators

In addition to the = operator, C allows you to combine arithmetic and bitwise operators with the = symbol to form augmented or compound assignment operator. The augmented operators offer a convenient shortcut for combining arithmetic or bitwise operation with assignment.

For example, the expression a+=b has the same effect of performing a+b first and then assigning the result back to the variable a.

Similarly, the expression a<<=b has the same effect of performing a<<b first and then assigning the result back to the variable a.

Here is a C program that demonstrates the use of assignment operators in C:

When you compile and execute the above program, it produces the following result −

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C Assignment Operators

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An assignment operation assigns the value of the right-hand operand to the storage location named by the left-hand operand. Therefore, the left-hand operand of an assignment operation must be a modifiable l-value. After the assignment, an assignment expression has the value of the left operand but isn't an l-value.

assignment-expression :   conditional-expression   unary-expression assignment-operator assignment-expression

assignment-operator : one of   = *= /= %= += -= <<= >>= &= ^= |=

The assignment operators in C can both transform and assign values in a single operation. C provides the following assignment operators:

In assignment, the type of the right-hand value is converted to the type of the left-hand value, and the value is stored in the left operand after the assignment has taken place. The left operand must not be an array, a function, or a constant. The specific conversion path, which depends on the two types, is outlined in detail in Type Conversions .

• Assignment Operators

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1. Introduction

2. History of C Language

3. Features of C Language

4. Use of C Language

5. C Language Download

6. Coding Vs. Programming

7. Structures in C

8. Difference Between Compiler and Interpreter

9. Difference Between Arguments And Parameters

10. C Program to Find ASCII Value of a Character

11. Define And include in C

12. What is Variables in C

13. Boolean in C

14. Conditional Statements in C

15. Constants in C

16. Data Types in C

17. Switch Case in C

18. Data Structures in C

19. C Compiler for Windows

20. C Compiler for Mac

21. Compilation process in C

22. Storage Classes in C

23. Array in C

24. One Dimensional Array in C

25. Two Dimensional Array in C

26. Dynamic Array in C

27. Array of Structure in C

28. Length of an Array in C

29. Array of Pointers in C

30. If Else Statement in C

31. Nested if else statement in C

32. Do While Loop In C

33. Nested Loop in C

34. For Loop in C

35. Difference Between If Else and Switch

36. If Statement in C

37. Operators in C

38. Bitwise Operators in C

39. C Ternary Operator

40. Logical Operators in C

41. Increment and decrement operators in c

42. Conditional operator in the C

43. Relational Operators in C

44. Assignment Operator in C

45. Unary Operator in C

46. Operator Precedence and Associativity in C

47. String Functions in C

48. String Input Output Functions in C

49. Function Pointer in C

50. Functions in C

51. Input and Output Functions in C

52. User Defined Functions in C

53. C Function Call Stack

54. Static function in C

55. Library Function in C

56. Toupper Function in C

57. Ceil Function in C

58. C string declaration

59. String Length in C

60. String Comparison in C

61. Pointers in C

62. Dangling Pointer in C

63. Pointer to Pointer in C

64. Constant Pointer in C

65. String Pointer in C

66. File Handling in C

67. Header Files in C

68. Stack in C

69. Stack Using Linked List in C

70. Linked list in C

71. Implementation of Queue Using Linked List

72. Heap Sort in C Program

73. Tokens in C

74. Enumeration (or enum) in C

75. Format Specifiers in C

76. Strcpy in C

77. Type Casting in C

78. Stdio.h in C

79. Transpose of a Matrix in C

80. Jump Statements in C

81. goto statement in C

82. Double In C

83. Comments in C

84. Types of Error in C

85. strcat() in C

86. Binary to Decimal in C

87. Pre-increment And Post-increment

88. C/C++ Preprocessors

89. How To Install C Language In Mac

90. Evaluation of Arithmetic Expression

91. Random Number Generator in C

92. Random Access Files in C

93. Pattern Programs in C

94. Palindrome Program in C

95. Prime Number Program in C

96. Hello World Program in C

97. Simple interest program in C

98. Anagram Program in C

99. Calculator Program in C

100. C Hello World Program

101. Structure of C Program

102. Program for Linear Search in C

103. C Program for Bubble Sort

104. C Program for Factorial

105. C Program for Prime Numbers

106. Reverse a String in C

107. C Program to Reverse a Number

108. C Program for String Palindrome

109. Debugging C Program

110. How to compile a C program in Linux

111. How to Find a Leap Year Using C Programming

112. Lcm of Two Numbers in C

113. Addition of Two Numbers in C

114. Armstrong Number in C

115. Recursion in C

116. Binary Search in C

117. Matrix multiplication in C

118. Overflow And Underflow in C

119. Dynamic Memory Allocation in C

120. Pseudo-Code In C

121. Fibonacci Series Program in C Using Recursion

122. Macros in C

123. Call by Value and Call by Reference in C

124. Identifiers in C

125. Factorial of A Number in C

126. strlen() in C

127. Convert Decimal to Binary in C

128. Command Line Arguments in C/C++

129. Strcmp in C

130. Square Root in C

String Input Output Functions in C

In the world of programming, strings serve as fundamental entities for the manipulation of textual data. They provide the means to handle and manipulate various forms of text, ranging from basic words to intricate documents, empowering developers to construct dynamic and interactive applications. To work with strings effectively, programming languages provide input and output functions specifically designed for handling string data. These functions allow developers to interact with users, display information, and process string-related operations. 

What is the Input and Output of a String in C?

Input functions are primarily used to obtain string data from external sources, such as user input or input streams. They enable the program to gather information and store it in variables for further processing.   Output functions, on the other hand, are responsible for displaying or writing string data to various destinations, such as the console, files, or output streams.  The commonly used standard IF statements in C are scanf() and printf().

How to Take Input of a String in C Without Spaces?

By following these steps, you can effectively obtain a string input output functions in C with examples including any whitespace characters.

1.Include the necessary header file:

This ensures that the required functions and definitions are available for input/output operations.

2. Declare a character array to store the string:

Here, we define an array called arr with a size of 200 characters. 

3. Display a prompt to the user:

This line informs the user about the expected input.

4. Use the scanf function to read the input:

In this line, scanf is employed to scan the input from the user. The format specifier %99[^ \t\n] specifies that it should read up to 99 characters (%99s) excluding whitespace characters ([^ \t\n]) . This ensures that any space, tab, or newline characters are skipped during input.

5. Process the input as desired:

Here, you can perform any desired operations on the obtained string. In this example, we simply print the input string using  printf .

6. End the program:

This statement terminates the program and returns the exit status.

Remember to adjust the size of the character array and perform appropriate error handling based on your specific needs.

Syntax for Using Scanf() Function in C

The syntax for using the  scanf() function in C is as follows:

Here's a breakdown of the syntax elements:

scanf: It is the name of the function used for input operations in C.

format:  It is a string that specifies the format of the input to be read. 

variable1, variable2, ...:  These are the variables where the input values will be stored. 

Working of Scanf() in C

The scanf() function in C facilitates input reading from the standard input stream, typically the keyboard, based on a specified format. It offers flexibility for reading various data types like integers, characters, strings, and more.

Here is a step-by-step breakdown of  scanf() functioning:

1. Format string:  As the initial argument of scanf() , the format string specifies the expected data types and their order. It employs format specifiers, starting with the % symbol, followed by a letter representing the desired data type.

2. Input retrieval: scanf() scans the input from the standard input stream, adhering to the provided format string. It begins reading characters and sequentially matches them with the format specifiers.

3. Format specifier matching:  When encountering a format specifier, scanf() attempts to read the input data from the standard input stream and convert it to the specified type. Prior to reading the actual input, it disregards leading whitespace characters, such as spaces, tabs, and newlines.

4. Value assignment: By utilizing the memory addresses of the variables passed as arguments after the format string (obtained using the & operator), scanf()  directly modifies their values, assigning the corresponding input values.

5. Return value: Upon completion, scanf() returns the count of successfully matched and assigned input items. This return value allows verification of whether the input was read correctly.

6. Error handling: It is essential to handle potential errors that may arise during scanf() usage. For instance, if the input doesn't match the format specifier or the input buffer overflows, scanf() may fail. Therefore, proper error handling is necessary to handle such scenarios effectively."

By following these steps and considering error handling, you can make effective use of the  scanf()  function in C for input operations.

Advantages of using scanf(): 

Versatility:  scanf() allows you to read input of various data types, such as integers, characters, strings, and more, by using appropriate format specifiers. It provides flexibility in handling different types of user input. 

Direct assignment: scanf() assigns the input values directly to variables using their memory addresses. This simplifies the process of capturing and using user input within the program. 

Disadvantages of using scanf(): 

Input errors:  scanf() can be prone to input errors and unexpected behavior. If the user enters incorrect data or the input format doesn't match the format specifier, it can result in incorrect or unpredictable program behavior. Error handling and input validation are crucial to mitigate these issues. 

Buffer overflow:  When reading input using scanf(), it's important to provide buffer sizes to avoid buffer overflow. If the input exceeds the capacity of the variables or arrays, it can lead to memory corruption and security vulnerabilities. 

Limited error reporting: scanf() returns the number of successfully matched and assigned input items, but it doesn't provide detailed information about the nature of errors. It can be challenging to identify and handle specific input errors using scanf() alone.

How to Take Input of a String With Spaces in C?

There are various methods to input a string with space and accept it in C:

Methods to Accept String With Space in C

There are 4 ways to accepts a string with space in C

Let's start with a character array (string) called str[]. As a result, we've declared a variable as char str[20].

Method 1 : Using gets

Syntax : char *gets(char *str)

Method 2 : Using fgets

Syntax : char *fgets(char *str, int size, FILE *stream)

 Example : fgets(str, 20, stdin); as here, 20 is MAX_LIMIT according to declaration.

Method 3 : Using %[^\n]%*c inside scanf

Example : scanf(“%[^\n]%*c”, str);

Explanation : The scanset character is [] in this case. ^\n informs the programme to accept input until a newline is encountered. Then, using this%*c, it reads newline characters, and the usage of * here denotes that these newline characters are ignored. 

Method 4 :  Using %[^\n]s inside scanf.

Example :  scanf(“%[^\n]s”, str); 

Explanation :  The scanset character is [] in this instance. ^\n instructs the programme to accept input until no newlines are found. Here, we utilized the XOR operator, which returns true until both letters are distinct. When a character is equal to New-Line ('n'), the XOR operator returns false, making it impossible to read the string. Therefore, we substitute "%[n]s" for "%s." Consequently, we may use scanf("%[n]s",str); to obtain a line of input with a space.

Comparison between gets() and fgets()

The user can define the maximum number of characters to read with the fgets() function, and we can also change the input stream to any file using fgets(), which is the key distinction between fgets() and gets(). Use of fgets() is secure since it checks the array bound, in contrast to gets(), which may be risky because it does not.

Using scanset %[ ] in scanf()

The scanset format specifier%[] provided by the scanf() function in C enables you to read input that contains spaces and other permitted characters. To match a set of characters supplied between brackets, use the scanset%[] function.

Ways by which we can use scanset to take input of a string in C with spaces

1. {%[^\n]%*c} inside scanf .

Let's explore one way to use scanset to take input of a string with spaces in C using the format specifier {%[^\n]%*c} inside scanf().

Here's an example:

In this example, we use the {%[^\n]%*c} format specifier inside scanf() to read a string with spaces. Let's break down the format specifier:

{ and }: The braces are literal characters that should match the input exactly. They help differentiate this format specifier from regular scanset format specifiers.

%[^\n]: This scanset format specifier matches a sequence of characters until a newline character ('\n') is encountered. It allows scanf() to read the input string with spaces.

%*c: The asterisk (*) indicates that the character read by this scanset format specifier should be discarded without assigning it to a variable. The %*c is used to read and discard the newline character after the scanset, preventing it from interfering with future input operations.

By using {%[^\n]%*c}, scanf() will read the input string until a newline character is encountered, effectively capturing the string with spaces. The string is then stored in the str array, and you can perform any necessary operations on it.

It's worth noting that the use of {%[^\n]%*c} is not a standard scanset format specifier, but rather a specific format we can define to achieve the desired input behavior.

2. %[^\n]s inside scanf

 In this example, %[^\n] is the correct scanset format specifier used in scanf(). It matches a sequence of characters until a newline character ('\n') is encountered. This allows scanf() to read the input string with spaces. After reading the input, the string is stored in the str array, and you can perform any necessary operations on it. 

How to Output a String With Spaces in C? 

1. using printf() with \n .

You can use the printf() function to output a string with spaces and include a newline character (\n) at the end to start a new line. Here's an example: 

In this example, we use printf() to output the string Hello, world! followed by a newline character (\n). The %s format specifier is used to print the string. 

The output will be: 

The newline character \n ensures that the next output appears on a new line.

2. using puts() 

The puts() function is specifically designed to output a string and automatically adds a newline character (\n) at the end. Here's an example: 

In this example, we use puts() to output the string Hello, world!. It automatically appends a newline character at the end of the string. 

Using puts() simplifies the process of printing a string with spaces and ensures that each output appears on a new line.

Strings play a crucial role in coding as they form the foundation for effective text manipulation. Their ability to store sequences of characters makes them versatile and applicable in various scenarios. By comprehending the unique properties of strings and mastering the input and output functions tailored for them, developers gain the ability to create dynamic and engaging applications across a wide range of domains. This understanding empowers programmers to harness the full potential of strings and leverage their capabilities for efficient text processing and manipulation.

1. What are C String Input/Output Functions?

String Output Functions in C are a set of functions in the C programming language that facilitate reading input from and writing output to strings.

2. What are some commonly used C String Input Functions?

Some commonly used String Input Functions in C include scanf(), gets(), and fgets(). These functions allow users to input strings from various sources like the console or files.

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