Decrement increment operator in C++,a--,a-+,a+-,a++

It is used to decrease the value of variable by 1 . For example we have variable a=3 and we want to decrement its value by 1 then we use decrement Operator.

int a=3;
a--;

 

So know the value of variable a will become 2.
Example 1

#include<iostream.h>
int main()
{
int a=5;
a--;
cout<<a;
system(“pause”);
return 0;
};

Output: 4

Example 2

#include<iostream.h>
int main()
{
int a=5;
a--;
a--;
cout<<a;
system(“pause”);
return 0;
};

Output: 3
 Post decrement: a--
In post decrement the cout statement is executed first and then variable is decremented. In this case the variable a is print first on the screen without any decrement in its value and then it is decrement by 1.

int a=4;
Cout<<a--;

Output: 4

Example 1

int a=4;
cout<<a--;
cout<<a;

Output: 4,3

In this program the variable a is decremented in the step 2 but it does not show it’s decremented value in step 2.In the step 3 variable a show its decremented value.
Example

#include<iostream.h>
int main()
{
int a=5;
a--;
cout<<a--;

system(“pause”);
return 0;
};

Output: 4
Pre decrement: --a
In pre decrement the cout statement t and the value of variable is decremented at the same time. In this case the variable a is print on the screen with its decremented value.

int a=4;
cout<<--a;

Output: 3

Example

int a=4;
--a;
Cout<<--a;

Output: 2
Example

#include<iostream.h>
int main()
{
int a=5;
--a;
cout<<a--;

system(“pause”);
return 0;
};

Output: 4

Example

#include<iostream.h>
int main()
{
int a=5;
a--;
cout<<--a;

system(“pause”);
return 0;
};

Output: 3