What are the performance differences between map and forEach in JavaScript?

What are the performance differences between map and forEach in JavaScript?

The map method creates a new array by applying a function to each element, while forEach executes a function on each element without returning a new array. Generally, map can be more performant when you need a new array, but forEach is faster for side effects.

Can you give me an example of when to use each?

Sure! Use map when you want to transform data, like converting an array of numbers to their squares. Use forEach when you want to perform an action for each element, like logging each number to the console.

Are there any scenarios where one is significantly better than the other?

Yes, if you need to create a new array based on existing data, map is the way to go. However, if you're just iterating for side effects, forEach is simpler and can be more readable.

What about performance in large datasets?

In large datasets, map may have a slight overhead due to creating a new array, while forEach might be faster since it doesn't return anything. However, the difference is often negligible unless you're working with very large arrays.