Arrays - Call by reference

Question

While passing an array to a function in java and then assigning it to a new array, I am getting the same old array.

public static void main(String[] args) {
        int[] arr1 = { 1, 2, 3, };
        changes(arr1);
        for (int val : arr1) {
            System.out.println(val);
        }
    }

private static void changes(int[] arr1) {
    int[] arr2 = { 7, 8, 9 };
    arr1 = arr2;
}

Why is it so when passing array deals with passing the reference to that array?

Also look at: [Changing array in method changes array outside](https://stackoverflow.com/questions/21653048/changing-array-in-method-changes-array-outside) — DontKnowMuchBut Getting Better, Sep 27 '20 at 19:57
Java is a pass-by-value language. The value of an object is a reference to the object. This includes arrays. — NomadMaker, Sep 27 '20 at 21:25

score 0 · Accepted Answer · answered Sep 27 '20 at 19:57

0

Because you are modifying the reference to arr1 locally (you can't modify the caller's reference). Change

arr1 = arr2;

to

System.arraycopy(arr2, 0, arr1, 0, arr2.length);

answered Sep 27 '20 at 19:57

Elliott Frisch

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Arrays - Call by reference

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