Java-Reference variable: this

class TestThisFunc {
    public static void main(String[] args) {
        System.out.println("Hello World!");
    }
}

class SomeClass {
    private int x = 0;
    private int y = 0;
    private int z = 0;

    SomeClass(int x) {
        this(x, 0, 0);
    }
    SomeClass(int x, int y) {
        this(x, y, 0);
    }
    SomeClass(int x, int y, int z) {
        if (x != 0) {}
        if (y != 0) {}
        if (z != 0) {}
    }
}