What is the difference between map and reduce in JavaScript?

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

Sure! The map method creates a new array by applying a function to each element of the original array, while reduce executes a reducer function on each element of the array, resulting in a single output value.

Can you give me an example of how to use both methods?

Of course! For map, you might have an array of numbers and want to double each number: const doubled = numbers.map(num => num * 2);. For reduce, if you want to sum those numbers, you could use: const sum = numbers.reduce((acc, num) => acc + num, 0);.

When should I use map instead of reduce?

Use map when you want to transform each element of an array into a new array. Use reduce when you want to derive a single value from an array, like a sum or an object.

Are there any performance differences between them?

Yes, generally map can be faster for simple transformations since it doesn't need to maintain an accumulator like reduce. However, the performance difference is usually negligible for small arrays.