Question

FOR JAVA (ZYBOOK) Write a method swapArrayEnds() that swaps the first and last elements of its array parameter. Ex: sortArray = {10, 20, 30, 40} becomes {40, 20, 30, 10}.

I can't modify/change any of the code. I can only add code to implement this where it says /* Your solution goes here */.

This is the code:

import java.util.Scanner;

public class ModifyArray {

/* Your solution goes here */

public static void main (String [] args) {
Scanner scnr = new Scanner(System.in);
int numElem = 4;
int[] sortArray = new int[numElem];
int i;
int userNum;

for (i = 0; i < sortArray.length; ++i) {
sortArray[i] = scnr.nextInt();
}

swapArrayEnds(sortArray);

for (i = 0; i < sortArray.length; ++i) {
System.out.print(sortArray[i]);
System.out.print(" ");
}
System.out.println("");
}
}

Answer 1

import java.util.Scanner;

public class ModifyArray {

    /* Your solution goes here */
    private static void swapArrayEnds(int[] sortArray) {
        // Storing first element to tmp
        int tmp = sortArray[0];
        // Replacing first element to last element
        sortArray[0] = sortArray[sortArray.length-1];
        // Replacing last element with value of variable tmp
        sortArray[sortArray.length-1] = tmp;
    }

    public static void main (String [] args) {
        Scanner scnr = new Scanner(System.in);
        int numElem = 4;
        int[] sortArray = new int[numElem];
        int i;
        int userNum;

        for (i = 0; i < sortArray.length; ++i) {
            sortArray[i] = scnr.nextInt();
        }

        swapArrayEnds(sortArray);

        for (i = 0; i < sortArray.length; ++i) {
            System.out.print(sortArray[i]);
            System.out.print(" ");
        }
        System.out.println("");
    }


}