JavaScript Break and Continue: Loop Flow Control & Labeled Statements

During loop execution, conditions frequently arise where continuing the loop is redundant or undesirable (such as finding a target record or encountering corrupted data). The break and continue statements provide precise, surgical control over loop execution flow.

1. The break Statement (Immediate Termination)

Used to bail out of a loop completely the moment a condition is satisfied:

const userDatabase = ["Alice", "Bob", "TargetUser", "David", "Eve"];

for (let i = 0; i < userDatabase.length; i++) {
    if (userDatabase[i] === "TargetUser") {
        console.log(`Target found at index ${i}! Stopping search.`);
        break; // Stops remaining iterations immediately!
    }
    console.log(`Checking user: ${userDatabase[i]}`);
}

2. The continue Statement (Skip Current Iteration)

Used to bypass the rest of the current iteration and jump straight to the next pass:

// Print only odd numbers between 1 and 10
for (let n = 1; n <= 10; n++) {
    if (n % 2 === 0) {
        continue; // Skip even numbers!
    }
    console.log(`Odd number: ${n}`);
}

3. Labeled Statements (Breaking Out of Nested Loops)

outerGrid: for (let r = 1; r <= 3; r++) {
    for (let c = 1; c <= 3; c++) {
        if (r === 2 && c === 2) {
            console.log("Trigger hit at [2,2]! Breaking outer grid.");
            break outerGrid; // Breaks BOTH inner and outer loops!
        }
        console.log(`Cell [${r},${c}]`);
    }
}

for (let i = 1; i <= 4; i++) {
    if (i === 2) continue;
    if (i === 4) break;
    console.log(i);
}