When should I use map vs forEach in JavaScript?

Can you explain the difference between map and forEach in JavaScript?

Sure! Both map and forEach are array methods, but they serve different purposes. map creates a new array by applying a function to each element, while forEach executes a function on each element without returning a new array.

When should I use map instead of forEach?

You should use map when you need to transform the elements of an array and create a new array from those transformations. Use forEach when you want to perform side effects, like logging or modifying external variables, without needing a new array.

Can you give me an example of each?

Of course! For map: const doubled = arr.map(num => num * 2); For forEach: arr.forEach(num => console.log(num)); The first creates a new array of doubled values, while the second just logs each number.

Are there any performance differences between them?

Generally, map can be slightly slower than forEach because it creates a new array. However, the difference is usually negligible unless you're working with very large arrays.