In java

1. prepend5() -- Given an array of ints, return a new array with the number 5 prepended at the start of the array.

prepend5([1, 2, 3]) [5, 1, 2, 3] prepend5([10]) [5, 10] prepend5([20, 42, 1, 6, 5]) [5, 20, 42, 1, 6, 5]

2. deleteFirst() -- Given an array of ints, delete the first element. Return the new array. The new array should be shorter than the given array. You may assume the given array contains at least one element.

deleteFirst([1, 2, 3]) [2, 3] deleteFirst([5, 4, 3, 2, 1]) [4, 3, 2, 1] deleteFirst([10]) []

3. deleteAt() -- Given an array of ints and an index, delete the element at the index. Shift the remaining elements down to fill the gap. Return a new array that is shorter than the given one. You may assume the index is valid.

deleteAt([1, 2, 3], 0) [2, 3] deleteAt([4, 5, 6], 1) [4, 6] deleteAt([9, 8, 7, 6, 5, 4], 4) [9, 8, 7, 6, 4]

4.indexOf() -- Given an array of ints and a target value, return the index of the target. If the target does not appear in the array, return -1. If the target appears multiple times, return the lowest index.

indexOf([1, 2, 3], 3) 2 indexOf([45, 10, 7, 10], 10) 1 indexOf([7, 6, 4, 5], 20) -1