Repository/HA1/ArrayManipulation.java

import java.util.Arrays;

public class ArrayManipulation {

   
    public static int[] reverseArray(int[] arr) {

        for (int i = 0; i < arr.length/2; i++) {
            int tmp = arr[i];
            arr[i] = arr[arr.length - 1 - i];
            arr[arr.length - 1 - i] = tmp;
         }
         return arr;

    }

    public static int[] removeFirst(int[] arr) {
        return Arrays.copyOfRange(arr, 1, arr.length);  // Copys the array "arr" from place 1 for the whole length of the array
 
    }
    
    
    public static int[] removeLast(int[] arr){
        int arr2[];
        if(arr.length<=1) return arr2 = new int[0]; //if array only has 1 elements, give empty array
        arr2 = new int[arr.length-1]; //else make new array with length one less
        for(int i=0; i<arr.length-1; i++){
            arr2[i]=arr[i]; //copy all but the last elements of original array
        }
        return arr2; //return new array
    }

    public static int[] squareEach(int[] arr) {

        for (int i = 0; i < arr.length; i++) {
            arr[i] = arr[i] * arr[i];
        }
        return arr;
    }

    public static void main(String[] args) {
       
        int[] arr = {1,2,3,4,5};
        System.out.println(Arrays.toString(removeFirst(arr))); // prints out the array on the Terminal which used the removefirst method
        System.out.println(Arrays.toString(removeLast(arr))); 
        System.out.println(Arrays.toString(squareEach(arr)));
        System.out.println(Arrays.toString(reverseArray(arr))); // prints out the array reversed on the Terminal which used the reversearray method
    }
}