C - Assignment Operators

In this tutorial we will learn about assignment operators in C programming language.

We use the assignment operators to assign the result of an expression to a variable.

In the following example we are assigning integer value 10 to a variable score of data type integer.

int score = 10;

Shorthand Assignment Operators

Lets say we have an integer variable and we have initially assigned 10 to it. Then lets say we increase the value by 5 and assign the new value to it.

//declare and set value
int x = 10;

//increase the value by 5 and re-assign
x = x + 5;

Another way to write the code x = x + 5 is by using the shorthand assignment += as shown below.

//declare and set value
int x = 10;

//increase the value by 5 and re-assign
x += 5;

Following is a list of shorthand assignment operators.

In the following example we are taking a value x from user then we are taking a new value y from user. Then we are adding y to x and assigning the result to x. Finally we are printing the new value stored in variable x.

#include <stdio.h>
int main(void)
{
  int x, y;
  
  printf("Enter the value of x: ");
  scanf("%d", &x);
  
  printf("Enter the value of y: ");
  scanf("%d", &y);
  
  // add y to x and re-assign
  x = x + y;
  
  printf("New value of x: %d\n", x);
  return 0;
}

Output

Enter the value of x: 10
Enter the value of y: 20
New value of x: 30

Another way of adding y to x and re-assigning the new value to x is by using the shorthand assignment operator +=.

#include <stdio.h>
int main(void)
{
  int x, y;
  
  printf("Enter the value of x: ");
  scanf("%d", &x);
  
  printf("Enter the value of y: ");
  scanf("%d", &y);
  
  // add y to x and re-assign
  x += y;
  
  printf("New value of x: %d\n", x);
  return 0;
}