• map and forEach are built-in JS iterators. They provider a cleaner interface for creating loops for using the for keyword.

# map

• map iterates over an array and executes a callback for each element in the array. The function will then return a new array.

# forEach

• forEach also iterates over an array and executes a callback for each element in the array. But the function will not return a new array. This is useful when you just want to perform a loop without the overhead of returning a new array. This is useful, for example, for saving every item in an array to a database.

# The difference?

map and forEach can both be used to loop an array. You could use map in every instance where you'd use forEach, but it'd be more performant to use forEach if you can discard the transformed values.