Java Pass By Value Test

JavaPassByValueTest.java

import java.util.*; 

public class MyClass {
  public static void main(String args[]) {
    ArrayList<String> a = new ArrayList<>();

    add1(a,"1");
    System.out.println("a:" + a); // Guess the output
    
    add2(a,"2");
    System.out.println("a:" + a); // Guess the output
  }
  
  public static void add1(List<String> list, String str) {
      list.add(str);
  }
  
  public static void add2(List<String> list, String str) {
      list = new ArrayList<>();
      list.add(str);
  }
}

// OUTPUT HERE:
// a:[1]
// a:[1]

// In add1(), it will work correctly to add str to the a list. 
// Because it continues to reference the original list, allowing modifications to persist.

// In add2(), it creates a new ArrayList then the local `list` point to that new object, it doesn't affect decreasedCv.
// The next adding also adds to that new object only.
// So the modification to original list is not persisted.