Please explain each line of code of what the code is doing, thank you :-)

import java.util.Arrays: public class BinarySearch { // return the index of the key in the sorted array a[]: -1 if not found public static int search(String key, String[] a) { return search(key, a, 0 , a.length): } public static int search(String key, String[] a, int lo, int hi) { // possible key indices in [lo, hi) if (hi 0) return search(key, a, lo, mid): else if (cmp