Constructor with fewer arguments from a constructor

Question

I have Constructor Tree(int a, int b, int c) and second Constructor Tree(int a, int b, int c, String s). How to load second constructor from first just to save writing all the logics? I thought about something like this but it gives me 'null' object.

public Tree(int a, int b, int c){
    Tree t1 = new Tree(a, b, c, "randomString");
}

Answer 1

The magic word is this, e.g.

public Tree( int a, int b, int c, String d ) {
    // Do something
}

public Tree( int a, int b, int c ) {
    this( a, b, c, "randomString" );
}