Assignment Operators in C/C++

Assignment operators are used to assigning value to a variable. The left side operand of the assignment operator is a variable and right side operand of the assignment operator is a value. The value on the right side must be of the same data-type of the variable on the left side otherwise the compiler will raise an error.
Different types of assignment operators are shown below:

• “=”: This is the simplest assignment operator. This operator is used to assign the value on the right to the variable on the left.
  For example:

  a = 10;
  b = 20;
  ch = 'y';
  

• “+=”: This operator is combination of ‘+’ and ‘=’ operators. This operator first adds the current value of the variable on left to the value on the right and then assigns the result to the variable on the left.
  Example:

  (a += b) can be written as (a = a + b)
  

  If initially value stored in a is 5. Then (a += 6) = 11.

• “-=”This operator is combination of ‘-‘ and ‘=’ operators. This operator first subtracts the current value of the variable on left from the value on the right and then assigns the result to the variable on the left.
  Example:

  (a -= b) can be written as (a = a - b)
  

  If initially value stored in a is 8. Then (a -= 6) = 2.

• “*=”This operator is combination of ‘*’ and ‘=’ operators. This operator first multiplies the current value of the variable on left to the value on the right and then assigns the result to the variable on the left.
  Example:

  (a *= b) can be written as (a = a * b)
  

  If initially value stored in a is 5. Then (a *= 6) = 30.

• “/=”This operator is combination of ‘/’ and ‘=’ operators. This operator first divides the current value of the variable on left by the value on the right and then assigns the result to the variable on the left.
  Example:

  (a /= b) can be written as (a = a / b)
  

  If initially value stored in a is 6. Then (a /= 2) = 3.

Below example illustrates the various Assignment Operators:

C

// C program to demonstrate
// working of Assignment operators

#include <stdio.h>

int main()
{

    // Assigning value 10 to a
    // using "=" operator
    int a = 10;
    printf("Value of a is %d\n", a);

    // Assigning value by adding 10 to a
    // using "+=" operator
    a += 10;
    printf("Value of a is %d\n", a);

    // Assigning value by subtracting 10 from a
    // using "-=" operator
    a -= 10;
    printf("Value of a is %d\n", a);

    // Assigning value by multiplying 10 to a
    // using "*=" operator
    a *= 10;
    printf("Value of a is %d\n", a);

    // Assigning value by dividing 10 from a
    // using "/=" operator
    a /= 10;
    printf("Value of a is %d\n", a);

    return 0;
}

C++

// C++ program to demonstrate
// working of Assignment operators

#include <iostream>
using namespace std;

int main()
{

    // Assigning value 10 to a
    // using "=" operator
    int a = 10;
    cout << "Value of a is "<<a<<"\n";

    // Assigning value by adding 10 to a
    // using "+=" operator
    a += 10;
    cout << "Value of a is "<<a<<"\n";

    // Assigning value by subtracting 10 from a
    // using "-=" operator
    a -= 10;
    cout << "Value of a is "<<a<<"\n";

    // Assigning value by multiplying 10 to a
    // using "*=" operator
    a *= 10;
    cout << "Value of a is "<<a<<"\n";

    // Assigning value by dividing 10 from a
    // using "/=" operator
    a /= 10;
    cout << "Value of a is "<<a<<"\n";

    return 0;
}

Output:

Value of a is 10
Value of a is 20
Value of a is 10
Value of a is 100
Value of a is 10