Solved (code is updated)
I'm having trouble finding out why my code is not working. I have the method that swaps the values and as far as I'm aware, it should be working. I've looked at this link here but I can't tell where I went wrong (I know it's not java, but the concept is the same) https://www.kirupa.com/html5/swapping_items_array_js.htm
Here is an example output of the code:
4
1
1
1
1
Provide two indicies to swap
0
2
4
1
1
1
1
/
import java.util.Scanner;
public class Test100 {
public static void main(String[] args) {
Scanner arrayScan = new Scanner(System.in);
int[] values = new int[5];
values[0] = 4;
values[1] = 1;
values[2] = 1;
values[3] = 1;
values[4] = 1;
System.out.println(values[0]);
System.out.println(values[1]);
System.out.println(values[2]);
System.out.println(values[3]);
System.out.println(values[4]);
// provide user input to choose values to swap
System.out.println("Provide two indicies to swap");
int userInput1 = Integer.valueOf(arrayScan.nextLine());
int userInput2 = Integer.valueOf(arrayScan.nextLine());
int inputArray1 = values[userInput1];
int inputArray2 = values[userInput2];
valSwap(values, userInput1, userInput2);
System.out.println(values[0]);
System.out.println(values[1]);
System.out.println(values[2]);
System.out.println(values[3]);
System.out.println(values[4]);
}
public static void valSwap(int[] array, int input1, int input2) {
int swapper = array[input1];
array[input1] = array[input2];
array[input2] = swapper;
}
}
I realized that I originally had been putting in the array indicie within my argument used inside the method when I called it. I changed that over to just the value the user entered because I realized I altered the method based off of what user @Joop Eggen had mentioned. I modified my method to match that and then altered the arguments when I called it.
Java was designed so that f(x) never changes a passed variable x. That is the (object) value of the variable is passed, not an "address" (reference) of some variable.
So swapping array positions:
void swap(int[] array, int index1, int index2) {
int temp = array[index1];
array[index1] = array[index2];
array[index2] = temp;
}
So swap(values, 2, 3) will never change values to point to null or an other array, but the array object may internally be changed.