C++ do...while Loop

Overview

The do...while loop is a control flow statement in C++ that executes a block of code repeatedly based on a boolean condition. Unlike a regular while loop, the do...while loop guarantees that the code block will be executed at least once, making it a valuable tool in scenarios requiring initial execution.

Key Concepts

• Execution Flow:
  1. The code inside the do block executes first.
  2. After executing the code, the condition is evaluated.
  3. If the condition is true, the loop repeats; if false, the loop ends.
• Use Case:
  • Ideal for situations where you want to ensure the loop executes at least once, such as prompting user input.

Syntax:

do {
    // Code to be executed
} while (condition);

Example

Here’s a simple example of a do...while loop that prints numbers from 1 to 5:

#include <iostream>
using namespace std;

int main() {
    int number = 1;

    do {
        cout << number << endl; // Output the current number
        number++;               // Increment the number
    } while (number <= 5);     // Continue while number is less than or equal to 5

    return 0;
}

Explanation

• Initialization: The variable number starts at 1.
• Loop Execution: The loop prints the number and increments it.
• Condition Check: The loop continues as long as number is less than or equal to 5.
• Output: The numbers 1 through 5 are printed to the console.

Conclusion

The do...while loop is beneficial for cases where the code block needs to run at least once, regardless of the condition. Mastering this loop can enhance your ability to manage repetitive tasks in C++ programming.