When I copy an array, the first array will change when I change a value of the second array? [duplicate]

Question

In Java for example:

int x[] = {1,2,3,4};
    
int y[] = x;
y[0] = 100;
System.out.println(x[0]);
System.out.println(y[0]);

Output:

100
100

How can I change the values of int y without changing values of int x?

Even though Java allows you to use int x[], that syntax is discouraged (and IMHO a historic mistake). The general convention is to use int[] x, as that is far more clear and readable to most Java programmers. — Mark Rotteveel
– Mark Rotteveel, Commented Jul 19, 2022 at 7:18

Suraj · Accepted Answer · 2022-07-19 05:42:43Z

1

You are pointing to same array location hence updating one will update the second.

Use clone() method to create copy of the array.

    int x[] = {1,2,3,4};
    
    int y[] = x.clone();
    y[0] = 100;
    System.out.println(x[0]);
    System.out.println(y[0]);

Output :

1
100

answered Jul 19, 2022 at 5:42

Suraj

3,1954 gold badges32 silver badges50 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

So there's no benefit in doing what we did before? I mean what is the point of y if I say int y = x;