break & continue

Sometimes you need to change a loop's normal flow before it finishes on its own: stop it entirely, or skip the rest of the current pass and move to the next one. C++ provides two keywords for exactly this: break and continue.

break: Exit the Loop Entirely

break immediately stops the innermost loop (or switch statement) it's inside, and execution resumes at the first line after that loop.

CPP

#include <iostream>
using namespace std;

int main() {
    for (int i = 1; i <= 10; i++) {
        if (i == 5) {
            break; // stop the loop entirely once i reaches 5
        }
        cout << i << " ";
    }
    cout << endl;
    // Output: 1 2 3 4

    return 0;
}

A very common use of break is searching for something and stopping as soon as it's found, instead of wastefully checking every remaining element.

CPP

#include <vector>
#include <iostream>
using namespace std;

int main() {
    vector<int> numbers = {4, 8, 15, 16, 23, 42};
    int target = 16;
    bool found = false;

    for (int n : numbers) {
        if (n == target) {
            found = true;
            break; // no need to keep looking
        }
    }

    cout << (found ? "Found it!" : "Not found.") << endl;
    return 0;
}

continue: Skip to the Next Iteration

continue skips the rest of the current iteration's body and jumps straight to the loop's next check (the condition in a while, or the increment step in a for). Unlike break, the loop keeps running — it just moves on early.

CPP

#include <iostream>
using namespace std;

int main() {
    for (int i = 1; i <= 10; i++) {
        if (i % 2 != 0) {
            continue; // skip odd numbers
        }
        cout << i << " ";
    }
    cout << endl;
    // Output: 2 4 6 8 10

    return 0;
}

break and continue in Nested Loops

When loops are nested, both break and continue only affect the innermost loop that contains them — the outer loop is completely unaffected and continues normally.

CPP

#include <iostream>
using namespace std;

int main() {
    for (int i = 1; i <= 3; i++) {
        for (int j = 1; j <= 3; j++) {
            if (j == 2) {
                break; // exits only the inner (j) loop
            }
            cout << "i=" << i << " j=" << j << endl;
        }
    }
    // Outer loop still runs all 3 times; inner loop stops early each time.

    return 0;
}

Note

C++ has no built-in "labeled break" like Java to exit multiple nested loops directly. The common, goto-free workarounds are: extracting the nested loops into their own function and using return, or setting a boolean flag that the outer loop checks. The goto statement technically can jump out of nested loops in one step, but it is almost universally discouraged in modern C++ because it makes control flow much harder to follow and reason about.

CPP

// A clean way to "break" out of nested loops: a flag checked by the outer loop.
bool stop = false;
for (int i = 0; i < 3 && !stop; i++) {
    for (int j = 0; j < 3; j++) {
        if (i == 1 && j == 1) {
            stop = true;
            break; // exits inner loop; outer loop exits on its next check
        }
        cout << i << "," << j << " ";
    }
}

Key Points

break exits the innermost loop (or switch) immediately; execution resumes after it.
continue skips the rest of the current iteration and moves on to the next one.
Both break and continue only affect the innermost enclosing loop in nested loops.
Use a boolean flag or a helper function with return to exit multiple nested loops cleanly.
goto can jump out of nested loops directly but is discouraged in idiomatic modern C++.