Java question

Given an array and a key, return an array that contains the locations of all elements that match the key. If no elements match the key, return an array with no elements. find All([5, 4, 5], 4) rightarrow [1] find All([5, 4, 5], 5) rightarrow [0, 2] find All([5, 4, 5], 6) rightarrow []