forEach() - Side Effects in JavaScript
From the JavaScript Array Methods cheat sheet · Iteration Methods · verified Jul 2026
forEach() - Side Effects
Execute function for each element (side effects only)
javascript
// Execute function for each element (no return)
[1, 2, 3].forEach(x => console.log(x));
// With index and array
arr.forEach((val, index, array) => {
console.log(`${index}: ${val}`);
});
// Can't break early (use for...of instead)💡 Use for side effects (logging, DOM updates)
⚠️ Cannot break/return early like for loop
📌 Returns undefined, not chainable
🔗 Use map() if you need transformed array
⚡ Skips empty slots in sparse arrays
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