C++ Do-While Loop

The do-while loop in C++ executes a block of code at least once and then continues looping as long as a given condition is true. It is useful when you want the loop body to run at least once regardless of the condition.

1. Basic Do-While Loop Example

This example prints numbers from 1 to 5 using a do-while loop.

#include <iostream>
using namespace std;

int main() {
    int i = 1;
    do {
        cout << i << endl;
        i++;
    } while(i <= 5);
    return 0;
}

2. Common Mistakes

A common mistake is not updating the loop variable inside the loop, which may lead to an infinite loop. Always ensure the condition will eventually become false.

#include <iostream>
using namespace std;

int main() {
    int i = 1;
    do {
        cout << i << endl;
        // i++ is missing, causing an infinite loop
    } while(i <= 5);
    return 0;
}

Conclusion

C++ do-while loops guarantee that the loop body executes at least once. Proper loop control ensures predictable and correct behavior of repetitive code execution.