How can i loop through parameter variables passed by function in java

July 7, 2022

This is my initial code,

public class Main {
    public static void main(String[] args) {

//   --------Declaring variables--------
        int arrLength = 6;
        String[] arr1 = new String[arrLength];
        String[] arr2 = new String[arrLength];
        String[] arr3 = new String[arrLength];
        
        joinArrays(arr1,arr2,arr3);
}

private static void joinArrays(String[] arr1, String[] arr2, String[] arr3){
        System.out.print("Array 1 : ");
        System.out.println(String.join(",",arr1));
        System.out.println("");

        System.out.print("Array 2 : ");
        System.out.println(String.join(",",arr2));
        System.out.println("");

        System.out.print("Array 3 : ");
        System.out.println(String.join(",",arr3));
        System.out.println("");

    }

But i need to do this in a loop (without using so much print methods).
I tried below way, but it only print out

Array 1 : arr1
Array 2 : arr2

likewise, it doesn’t join the list that passed to the parameter.

private static void joinArrays(String[] arr1, String[] arr2, String[] arr3){
        for(int i = 0; i<3;i++){
          System.out.print("Array "+i+" : ");
          System.out.println(String.join(",","arr"+i));
          System.out.println("");
   }
}

How can i do this looping thing easy.

>Solution :

There is no (easy) way to iterate through the arguments passed to a method in Java.

If you want to prevent repeating yourself, then you can put the code in a separate method, and call that with the argument variables one at a time:

private static void joinArrays(String[] arr1, String[] arr2, String[] arr3) {
    joinArray("Array 1 : ", arr1);
    joinArray("Array 2 : ", arr2);
    joinArray("Array 3 : ", arr3);
}

private static void joinArray(String label, String[] arr) {
    System.out.print(label);
    System.out.println(String.join(",", arr));
    System.out.println("");
}