do-while, break and continue

do-while

A do-while loop checks its condition at the end, so the block always runs at least once. It is perfect for menus and “ask again” input:

#include <iostream>
using namespace std;

int main() {
    int guess;
    do {
        cout << "Guess the number (1-10): ";
        cin >> guess;
    } while (guess != 7);
    cout << "Correct!\n";
    return 0;
}

Input (what the user types)

3
9
7

Output

Guess the number (1-10): Guess the number (1-10): Guess the number (1-10): Correct!

Common mistake: A do-while ends with a semicolon after the condition: } while (guess != 7);

break: leave the loop now

break stops the loop immediately, even if the condition is still true:

#include <iostream>
using namespace std;

int main() {
    for (int i = 1; i <= 10; i++) {
        if (i == 4) {
            break;
        }
        cout << i << "\n";
    }
    cout << "Loop finished early\n";
    return 0;
}

Output

1
2
3
Loop finished early

continue: skip to the next round

continue skips the rest of this round and jumps to the next one:

#include <iostream>
using namespace std;

int main() {
    for (int i = 1; i <= 10; i++) {
        if (i % 3 == 0) {
            continue;          // skip 3, 6 and 9
        }
        cout << i << " ";
    }
    cout << "\n";
    return 0;
}

Output

1 2 4 5 7 8 10 

Think of it like this: break is leaving the cinema in the middle of the film. continue is skipping one boring song but staying for the rest of the playlist.