javascript - Main difference between map and reduce

Question

I used both methods but I am quite confused regarding the usage of both methods.

Is anything that map can do but reduce can not and vice versa?

Note: I know how to use both methods I am questioning for main difference between these method and when we need to used.

Answer 1

Source

Both map and reduce have as input the array and a function you define. They are in some way complementary: map cannot return one single element for an array of multiple elements, while reduce will always return the accumulator you eventually changed.

map

Using map you iterate the elements, and for each element you return an element you want.

For example, if you have an array of numbers and want to get their squares, you can do this:

// A function which calculates the square
const square = x => x * x

// Use `map` to get the square of each number
console.log([1, 2, 3, 4, 5].map(square))