C Modify Operators

Modifying operators:

• Modify operators also called unary operators.
• Modify operators are Increment and Decrement operators.
• Increment operator increase the value of variable by 1
• Decrement operator decrease the value of variable by 1

Increment operators is of two types
1) pre-increment
2) post-increment

Decrement operators is of two types
1) pre-decrement
2) post-decrement

Expression with modify operators use following steps for evaluation:

1. Pre-increment / Pre-decrement
2. Substitution of values
3. Evaluation based on priorities
4. Assignment to variable
5. Post-increment / Post-decrement

Execution of Pre-increment operator:

#include<stdio.h>
main()
{
	int a=10,b;
	b = ++a;
	printf("%d,%d",a,b);
}

Execution of Post-increment operator:

#include<stdio.h>
main()
{
	int a=10,b;
	b = a++;
	printf("%d,%d",a,b);
}

If an expression contains both pre-increment and post-increment operators, first pre-increment operators evaluate and the values will be substituted. After execution of expression, the post-increment values will be substituted into variables.

#include<stdio.h>
main()
{
	int x=10,y=20,z;
	z = x++ * --y ;
	printf("%d,%d,%d",x,y,z);
}