What are the differences between map, filter, and reduce in JavaScript?

Can you explain the differences between map, filter, and reduce in JavaScript?

Sure! In JavaScript, map, filter, and reduce are array methods that help manipulate data. map creates a new array by applying a function to each element, filter creates a new array with elements that pass a test, and reduce reduces the array to a single value based on a function.

Can you give me an example of each?

Of course! For map, if you have an array of numbers and want to double them, you can use array.map(num => num * 2). For filter, if you want to get only even numbers, you can use array.filter(num => num % 2 === 0). For reduce, if you want to sum all numbers, you can use array.reduce((acc, num) => acc + num, 0).

What are the performance differences between them?

Performance can vary based on the size of the array and the complexity of the function used. Generally, map and filter iterate through the array once, while reduce can be more complex as it accumulates values. However, the differences are often negligible for small arrays.

When should I use each of these methods?

Use map when you want to transform data, filter when you need to select specific elements, and reduce when you want to compute a single value from an array.