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) {
  }
 }
}