I am trying to reverse an array the user inputs like {hello, Donald, Trump} -> pmurT, dlanoD etc but it outputs [null]

I'm new to java and wanted to reverse an array the user inputs (including character) so apple, banana becomes ananab, elppa. But it outputs [null]

package test;

import java.util.Arrays;
import java.util.Collections;

import javax.swing.JOptionPane;

public class WhileWarmup{

	public static void main(String[] args) {
		String shoppinglist = JOptionPane.showInputDialog("What do you want to manipulate");
		String[]Shoppinglist = shoppinglist.split(",");
		String[]Shoppinglist1 = shoppinglist.split(",");
		
		int num = Shoppinglist.length;
		String bruh = "";
		String bruh1 = "";
		while (num >= 0) {
			Shoppinglist1 = Arrays.copyOfRange(Shoppinglist,num,num + 1);
			Collections.reverse(Arrays.asList(Shoppinglist1));
			bruh1 =  Arrays.toString(Shoppinglist1);
			bruh = bruh + bruh1;
			num = num - 1;
		    System.out.println(bruh);
        }
    }
}

When it comes to reversing a String, StringBuilder#reverse is always there:

	public static void main(String[] args) {
		List<String> wordList = Arrays.asList("hello", "Donald", "Trump");
		System.out.println(reverseListAndItsElements(wordList));
	}

	public static List<String> reverseListAndItsElements(List<String> list) {
		List<String> reversed = new ArrayList<>(list);//Create a copy
		Collections.reverse(reversed);
		return reversed.stream().map(s -> new StringBuilder(s).reverse().toString())
            .collect(Collectors.toList());
	}

Prints:

[pmurT, dlanoD, olleh]


And in case you do not want to mess with lists:

public static void main(String[] args) {
	String original = "hello,Donald,Trump";
	String[] split = original.split(",");
	String[] reversedSplit = new String[split.length];
	IntStream.range(0, split.length).forEach(index -> {
		reversedSplit[index] = new StringBuilder(split[index]).reverse().toString();
	});
	System.out.println(Arrays.toString(reversedSplit));
}

Try this.

String[] input = {"hello", "Donald", "Trump"};
String[] reversed = new StringBuilder(String.join(",", input))
    .reverse().toString().split(",");
System.out.println(Arrays.toString(reversed));

output:

[pmurT, dlanoD, olleh]

you can use the following code

public static List<String> reverseList(List<String> list) {
        List<String> reversed = new ArrayList<>(list);
        Collections.reverse(reversed);
        return reversed.stream().collect(Collectors.toList());
    }

This code can be used for String array reverse implementation. There are many ways of reversing a string. One is using StringBuilder I have used.

public class Main
{
 static String[] arr={"hello", "Donald", "Trump"};
  public static void main (String[]args)
 {
String[] strA=  reverseTheString(arr);

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

// This is actual method for reverse an array elements.

public static String[] reverseTheString(String[] arr){
 String[] reverseArray=new String[arr.length];
int j=arr.length-1;

for(int i=0;i<arr.length;i++)
  {
      StringBuilder sb=new StringBuilder(arr[i]);
    reverseArray[j]=sb.reverse().toString();
    j--;
 }
return reverseArray;
 }
}