When do i use array lists over regular arrays?

Question

It seems like they serve the same function, but there must be some reason both exist. Is one more efficient than the other?

Answer 1

If I know how many numbers or whatever I want to save, I use arrays. Because you have to know the size of your array.

int[] number = new int [5];

If I don't know it I use a list.

ArrayList number =
new ArrayList ();

Answer 2

A list is also useful if you want to sort: https://www.sololearn.com/learn/Java/2183/?ref=app

Answer 3

An Array is a static object, List are collections so you may program to interfaces as bestpractices recommends.

For example: Given an array remove all elements when also exists at least one that is the double of it and return a sorted array of selectrd elements. This is better to wrap the array operate over it as a collection and then convert to array again.