C - increment operator

The increment (++) is an unary operator in C and hence acts upon a single operand to produce a new value. It has two variant:

• Pre-increment: Increases the value of the operand by 1, then returns the operand.
• Post-increment: Returns the operand, then increases the value of the operand by 1.

Example: Pre-increment operator

The example below describes the usage of pre-increment operator.

#include <stdio.h>
 
int main (){
  int x = 10;
  int y = 20;
  int z;

  //below expression is equivalent to
  //x = x + 1; z = x + y;
  z = ++x + y;    

  //Displaying the result
  printf("x = %d\n", x);
  printf("y = %d\n", y);
  printf("z = %d\n", z);
  return 0;
}

The output of the above code will be:

x = 11
y = 20
z = 31

Example: Post-increment operator

The example below describes the usage of post-increment operator.

#include <stdio.h>
 
int main (){
  int x = 10;
  int y = 20;
  int z;

  //below expression is equivalent to
  //z = x + y; x = x + 1; 
  z = x++ + y;    

  //Displaying the result
  printf("x = %d\n", x);
  printf("y = %d\n", y);
  printf("z = %d\n", z);
  return 0;
}

The output of the above code will be:

x = 11
y = 20
z = 30