Table of Contents
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
- For loop
- while loop
- Do-while loop
In this post, we are going to learn the While in Cpp programming language. with example program
Syntax
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| Syntax in while loop in C++ |
How while loop works
- First, the test expression evaluates the test expression only once
- When the test expression is true. statements inside the body of while loop is executed.
- this process happening on until the test expression is false
- When the test expression is false, The control exits from the loop body and while-loop is terminated
Flow diagram
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| Flow diagram of While loop in C++ |
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