The Increment and Decrement Operators in C are some of the operators which are used to increase or decrease the value by 1. For instance, Incremental operator ++ is used to increase the existing variable value by 1 (x = x + 1). And decrement operator – – is used to decrease or subtract the existing value by 1 (x = x – 1).
The syntax of the increment and decrement operators in C Programming to prefix and postfix is:
- Increment Operator : ++x or x++
- Decrement Operator: –x or x–
Increment and decrement operators in C Example
Let’s see one example of increment and decrement operators to get a better idea!
#include <stdio.h>
int main()
{
int x = 10,y = 20;
printf("----INCREMENT OPERATOR EXAMPLE---- \n");
printf("Value of x : %d \n", x); //Original Value
printf("Value of x : %d \n", x++); // Using increment Operator
printf("Value of x : %d \n", x); //Incremented value
printf("----DECREMENT OPERATOR EXAMPLE---- \n");
printf("Value of y : %d \n", y); //Original Value
printf("Value of y : %d \n", y--); // using decrement Operator
printf("Value of y : %d \n", y); //decremented value
return 0;
}
At Line 7, we used the increment operator. So the value of the X was returned first (i.e., 10), and then the X value was incremented by 1.
Line 8: We called the X value again; it displays 11 because the value has already been updated. Same with the decrement operator.
Prefix and Postfix
If you observe the above prefix and postfix syntax, we can assign the C increment and decrement operators either before the operand or after the operand. When ++ or — is used before operand like: ++x, –x then we call it as prefix, if ++ or — is used after the operand like: x++ or x– then we called it as postfix.
Let’s explore the prefix and postfix
- ++i (Pre-increment): It will increment the value of i even before assigning it to the variable i.
- i++ (Post-increment): The operator will return the variable value first (i.e, i value) then only i value is incremented by 1.
- –i (Pre decrement): It will decrement the value of i even before assigning it to the variable i.
- i– (Post decrement): The operator returns the variable value first (i.e., i value), then only i value decremented by 1.
Prefix and Postfix Example
This Program shows how to use Increment and Decrement Operators as a Prefix and Postfix in C.
#include<stdio.h>
int main()
{
int x = 10,y = 20, a = 5, b= 4;
printf("---- PRE INCREMENT EXAMPLE---- \n");
printf("Value of x : %d \n", x); //Original Value
printf("Value of x : %d \n", ++x); // using Pre increment Operator
printf("Value of x Incremented : %d \n", x); //Incremented value
printf("----POST INCREMENT EXAMPLE---- \n");
printf("Value of y : %d \n", y); //Original Value
printf("Value of y : %d \n", y++); // using Post increment Operator
printf("Value of Incremented y : %d \n", y); //Incremented value
printf("----PRE DECREMENT EXAMPLE---- \n");
printf("Value of a : %d \n", a); //Original Value
printf("Value of a : %d \n", --a); // using Pre decrement Operator
printf("Value of decremented y : %d \n", a); //decremented value
printf("----POST DECREMENT EXAMPLE---- \n");
printf("Value of b : %d \n", b); //Original Value
printf("Value of b : %d \n", b--); // using Post decrement Operator
printf("Value of decremented b : %d \n", b); //decremented value
return 0;
}
Output
---- PRE INCREMENT EXAMPLE----
Value of x : 10
Value of x : 11
Value of x Incremented : 11
----POST INCREMENT EXAMPLE----
Value of y : 20
Value of y : 20
Value of Incremented y : 21
----PRE DECREMENT EXAMPLE----
Value of a : 5
Value of a : 4
Value of decremented y : 4
----POST DECREMENT EXAMPLE----
Value of b : 4
Value of b : 4
Value of decremented b : 3 Although increment and decrement operators are used in For Loop, While, and Do-While loops, we are not given an example. Because it is too early to understand the loop concept. Try to understand the concept of the prefix and postfix in C. This Operator helps you to understand if statement, For Loop, While and Do-While loop Program syntax in the C Programming easily
