Output

with a new array: 10
with a new array and new value: 10
with a new value: 42

PlayingWithArrays.java

public class PlayingWithArrays {

    public static void setToNewArray(int[] x) {
        x = new int[1];
        /*
         
         x is passed by value, assigning it a new array won't change its state outside the body of the function
         
         */
    }

    public static void setToNewArrayAndValue(int[] x) {
        x = new int[1];
        x[0] = 42;
        /*
         
         x is a new array only within the function once again (passed by value)
         so setting the first element of that array to 42 only change the internal state of the function, not outside
         
         */
    }

    public static void setValue(int[] x) {
        x[0] = 42;
        /*
         finally, changing the value of an element of the array changes the state outside the scope of the function, like with objects
         */
    }

    public static void main(String[] args) {
        int[] x = {10, 20, 30};
        setToNewArray(x);
        System.out.println("with a new array: " + x[0]);
        setToNewArrayAndValue(x);
        System.out.println("with a new array and new value: " + x[0]);
        setValue(x);
        System.out.println("with a new value: " + x[0]);
    }
}