Increment Operator & Decrement Operator (++, --)

Increment Operrator (++)

count + 1 = 1
count + 1 = 2
count + 1 = 3

Increase number by 1

a = 5
a - 1 = 4
a - 2 = 3

Decrease count by 1

Increment Operator

* Inc Operator :
1. Pre-Increment
ex : ++number;
(first increase then use)

2. Post-Increment
ex : number++;
(first use then increase)

Example 1 :

#include <iostream>
using namespace std;

int main() {

    int a=10;

    cout<<"initial value of a : "<<a<<"\n";

    a++;

    cout<<"value of a : "<<a<<"\n";

    return 0;
}

Output :

initial value of a : 10

value of a : 11

Explanation :

Line 6 : Declare a variable and its value is 10.
Line 8 : Print initial value of a : and a using cout.
Line 10 : a++ Post Increment operator .
Line 12 : Print value of a : and a using cout.

Example 2 :

#include <iostream>
using namespace std;

int main() {


    int a=10;

    cout<<"initial value of a : "<<a<<"\n";

    ++a;

    cout<<"value of a : "<<a<<"\n";

    return 0;
}

Output :

initial value of a : 10

value of a : 11

Explanation :

Line 6 : Declare a variable and its value is 10.
Line 8 : Print initial value of a : and a using cout.
Line 10 : --a Pre Increment operator .
Line 12 : Print value of a : and a using cout.

Example 3 :

#include <iostream>
using namespace std;

int main() {

    int a = 10;
    cout<<"initial value of a :"<<a<<"\n";

    int count = a++;
    cout<<"value of count : "<<count<<"\n";

    cout<<"initial value of a : "<<a<<"\n";

    return 0;
}

Output :

initial value of a : 10

value of count : 10

initial value of a : 11

Explanation :

Line 6 : Declare a variable and its value is 10.
Line 7 : Print initial value of a : and a using cout.
Line 9 : Initialized count value and assign a++ .
Line 10 : Print value of count : and count variable.
Line 11 : Print initial value of a : and a variable.

Example 4 :

#include <iostream>
using namespace std;

int main() {

    int a = 10;
    cout<<"initial value of a :"<<a<<"\n";

    int count = ++a;
    cout<<"value of count : "<<count<<"\n";

    cout<<"initial value of a : "<<a<<"\n";

    return 0;
}

Output :

initial value of a : 10

value of count : 11

initial value of a : 11

Explanation :

Line 6 : Declare a variable and its value is 10.
Line 7 : Print initial value of a : and a using cout.
Line 9 : Initialized count value and assign ++a .
Line 10 : Print value of count : and count variable.
Line 11 : Print initial value of a : and a variable.

Decrement Operator

* Dec Operator :

1. Pre-Decrement
ex : --number;
(first decrease then use)

2. Post-Decrement
ex : number--;
(first use then decrease)

Example 5 :

#include <iostream>
using namespace std;

int main() {

    int a = 10;

    cout<<"initial value of a : "<<a<<"\n";

    int count = --a;

    cout<<"value of count : "<<a<<"\n";

    cout<<"value of a : "<<a"\n";

    return 0;
}

Output :

initial value of a : 10

value of count : 9

value pf a : 9

Explanation :

Line 6 : Declare a variable and its value is 10.
Line 7 : Print initial value of a : and a using cout.
Line 9 : Initialized count value and assign --a .
Line 10 : Print value of count : and count variable.
Line 11 : Print initial value of a : and a variable.

Example 6 :

#include <iostream>
using namespace std;

int main() {

    int a = 10;

    cout<<"initial value of a : "<<a<<"\n";

    int count = a--;

    cout<<"value of count : "<<a<<"\n";

    cout<<"value of a : "<<a"\n";

    return 0;
}

Output :

initial value of a : 10

value of count : 10

value pf a : 9

Explanation :

Line 6 : Declare a variable and its value is 10.
Line 7 : Print initial value of a : and a using cout.
Line 9 : Initialized count value and assign a-- .
Line 10 : Print value of count : and count variable.
Line 11 : Print initial value of a : and a variable.

Example 7 :

#include <iostream>
using namespace std;

int main() {

    int num = 15;
    cout<<"Number : "<<num<<"\n";

    int count = num++;
    cout<<"Count : "<<count<<"\n";

    count = --num;
    cout<<"Count : "<<count<<"\n";

    num++;

    cout<<"Number : "<<num<<"\n";

    return 0;
}

Output :

Number : 15

Count : 15

Count : 15

Number : 16

Explanation :

Line 6 : Declare num variable and assign value 15 .
Line 7 : print Number : num.
Line 9 : declare count variable assign num++ .
Line 10 : print Count : count .
Line 12 : assign --num into count variable .
Line 13 : print Count : count .
Line 15 : num++
Line 16 : print Number : num.