Confusing return statment

Question

Trying to pass x from method to another, then sum it before printing it in main. The program works perfectly, but 8th line is confusing me. I need a brief breakdown of this code, which I obtained after following the IDE's errors warnings

1 package tttt;
2
3 public class Class {
4
5   public static int test() {
6
7       int x = 1;
8       return test2(x);
9
10  }
11
12  public static int test2(int a) {
13       a += 2;
14       return a;
15
16  }
17 }

package tttt;

public class fff {

    public static void main(String[] args) {
    
    
        System.out.println(Class.test());
    }

}

Answer 1

i left the comments in your code. You can return links on data structures (List, Queue, Map) or literals like Numbers.

1  package tttt;
2
3  public class Class {
4
5    // The main method named 'test'
6    public static int test() {
7
8        // Declare and initialize a variable 'x' with the value 1
9        int x = 1;
10
11       // Call the method 'test2' with the argument 'x' and return its result
12       return test2(x);
13
14   }
15
16   // Another method named 'test2' with an integer parameter 'a'
17   public static int test2(int a) {
18       // Increment the parameter 'a' by 2
19       a += 2;
20
21       // Return the modified value of 'a'
22       return a;
23
24   }
25 }

All differences arise when you pass the value of a variable that is an array; the variable's value becomes a reference to the original array. If you modify it in another method as an argument, you will alter the original array.

class Main {
    public static void main(String[] args) {
        int[] d = Class.test();
        
        for (int i : d){
                System.out.println(i); /// 1, 2, 10
        }
    }
}

class Class {
    public static int[] test() {
        int[] x = {1, 2, 3};
        test2(x);
        return x;
    }

    public static void test2(int[] a) {
        a[2] = 10;
    }
}