While loop in C++ programming language

While loop in C++ programming language

In this article, we discuss the While in C++ programming language.

In the C++ programming language, the while loop used to executes the block of code repeatedly until the particular condition is satisfied.

 

Generally, loops are used to repeat a block of code

C++ language has three types of loops

1. For loop
2. while loop
3. Do-while loop

Test Expression is checked on each and every entry of the while loop

 

While loop programs

Program 1

This program used to display natural numbers 1 to 10

#include <iostream>

using namespace std;

int main()
{
int counter=1; // initialized variable
while(counter<=10) //Test expresiion
{
cout << counter<<"-> number of student" << endl; //Display statement
counter++;  //Increment statement
}

return 0;
}

 

When the above code is executed it produces the following result

Programme 2

This program allows to enter a number and calculate the factorial of given number

#include <iostream>
using namespace std;

int main() {
int number, i = 1, factorial = 1;
cout<< "Enter a positive integer: ";
cin >> number;

while ( i <= number) {
factorial *= i;      //factorial = factorial * i;
++i;
}

cout<<"Factorial of "<<number<<" = "<<factorial;
return 0;
}

 

When the above code is executed it produces the following result

Program 3

The program allows the user to enter a number and calculates sum of 1 to given number

#include <iostream>
#include <conio.h>
using namespace std;

int main()
{
    int num,sum=0;

    cout << "Enter a positive integer" << endl;
    cin>>num;
    int i=1;
    while(i<=num){
        sum+=num;  //sum=sum+num;
        i++;
    }
    cout<<"The sum of 1 to "<<num<<" : "<<sum;
    getch();
    return 0;
}

When the above code is executed it produces the following result

Enter a positive integer
40
The sum of 1 to 40 : 1600