Increment and Decrement Operators

C language permits two very useful operators not commonly found in other languages. Those are increment and decrement operators, ++ and --. The operation ++ adds 1 to its single operand and -- subtracts 1. Thus, the following are equivalent operations: -

x = x+1;

is the same as

x++; or ++x;

and

x = x - 1;

is the same as

x--; or --x;

The increment and decrement operators might either precede or follow the operand. Thus,  there  is  a  difference  whenever  they  are  used  in  expressions.  Whenever an increment or decrement operator precedes its operand, C++ language performs the increment or decrement operation prior to by using the operand's value. C uses the value of the operand's value after incrementing or decrementing it if the operator follows its operand.

Let consider the following example:

x = 10;

y = ++x;

In the given case, y is set to 11.

Therefore, if the code had been written as x = 10;

y = x++;

y would have been set to 10. With both the cases, x is set to 11; the difference is, whenever it occurs.

Let's see how different types of arithmetic operators can be used in a program:-

# include <iostream.h>

main()

{

int a, b, c, d, x, y, p, q;

a=20; b=35; c= a+b; d= b-a;

cout<<"******Addition AND Subraction*****";

cout<<"a = "<<"b =\n"<< a<< b;

cout<<" c = "<<"d = \n"<<c<<d;

x = b / a;

y = b % a;

cout<<"******Division AND Modulus******";

cout<<"x =\n"<<x;

cout<<"y = \n"<<y);

p=++a;

q= c + b--;

cout<<"******Increment AND Decrement******";

cout<<"a = \n"<<a);

cout<<"b =\n"<<b);

cout<<"p = \n"<<p);

cout<<"q = \n"<<q);

}

The output is:

Addition AND Subraction a=20 b = 35 c= 55 d = 15

Division AND Modulus  x= 1 y= 15

Increment AND Decrement a= 21 b= 34 p= 36 q= 71