While loop in Programming

A while loop is a control structure that repeatedly executes a block of code as long as a specified condition remains true.

The condition is checked before each iteration, and the loop stops once the condition becomes false.
It is useful when the number of iterations is not known beforehand.

C++

#include <iostream>
using namespace std;

void printNumbers() {

    int count = 0;

    // while loop runs while the condition is true
    while (count < 5) {
        cout << count << endl;
        count++;
    }
}

int main() {

    // Calling the function
    printNumbers();

    return 0;
}

Java

public class GfG{

    // Function that prints numbers using while loop
    public static void printNumbers() {

        int count = 0;

        // while loop runs while the condition is true
        while (count < 5) {
            System.out.println(count);
            count++;
        }
    }

    public static void main(String[] args) {

        // Calling the function
        printNumbers();
    }
}

Python

def print_numbers():

    # Function that prints numbers using while loop
    count = 0

    # while loop runs while the condition is true
    while count < 5:
        print(count)
        count += 1


# Calling the function
print_numbers()

using System;

public class GfG
{
    public static void PrintNumbers()
    {
        int count = 0;

        // while loop runs while the condition is true
        while (count < 5)
        {
            Console.WriteLine(count);
            count++;
        }
    }

    public static void Main()
    {
        // Calling the function
        PrintNumbers();
    }
}

JavaScript

function printNumbers() {

    // Function that prints numbers using while loop
    let count = 0;

    // while loop runs while the condition is true
    while (count < 5) {
        console.log(count);
        count++;
    }
}

// Calling the function
printNumbers();

Explanation:
The code initializes count = 0 and runs a while loop while count < 5. In each iteration, the current value of count is printed using cout, and then count is incremented by 1.

Working:
The loop starts from 0, prints the value, and increases it by 1 in every iteration. When count becomes 5, the condition count < 5 becomes false, so the loop terminates.

Use Cases of While Loop:

Input Validation: Repeatedly ask for input until the user provides a valid value.
Processing Data: Traverse arrays, lists, or collections until a condition is met.
Event Handling: Continuously monitor events like sensor data or network requests.
Implementing Algorithms: Used in algorithms such as searching, sorting, and mathematical computations.
State Machines: Execute logic repeatedly until a state change occurs.
Games and Simulations: Run the main game loop to update state, process input, and render output.
Batch Processing: Process multiple tasks (files, records, etc.) until all items are handled.

While loop in Programming

Use Cases of While Loop:

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