Invoking Overloaded Constructors Through this( )

In Java this keyword can call the overloaded constructors.

The general form is shown here:

this(arg-list)

When this( ) is executed, the overloaded constructor that matches the arg-list is executed first.

The call to this( ) must be the first statement within the constructor.


class MyClass {
  int a;
  int b;

  // initialize a and b individually
  MyClass(int i, int j) {
    a = i;
    b = j;
  }

  // initialize a and b to the same value
  MyClass(int i) {
    this(i, i); // invokes MyClass(i, i)
  }

  // give a and b default values of 0
  MyClass() {
    this(0); // invokes MyClass(0)
  }
}

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