Confusion about call-by -value and call - by reference

Question

class A{
public boolean check(String source, ArrayList arr){
//pROCESS ON ARRAYLIST
class B {
A con = new A();
String source="this is string ";
ArrayList arr = new ArrayList();
// suppose Arraylist has some elements
boolean  error= false;
error = A.check(source,arr);
}Is it call by value or call by ref .
Please help
}

Answer 1

Object references are also passed by value. ???Yes, as demonstrated byclass Foo {
    public int bar = 0;
    public static void main(String[] args) {
            Foo foo = new Foo();
            foo.bar = 1;
            System.out.println(foo.bar);
            baz(foo);
            // if this was pass by reference the following line would print 3
            // but it doesn't, it prints 2
            System.out.println(foo.bar);
    private static void baz(Foo foo) {
        foo.bar = 2;
        foo = new Foo();
        foo.bar = 3;
}