Calling one constructor from another

[merlin bar]

public class Test{
  public Test(){
    System.out.println("Test()");
  }
                                                                                
  public Test( int a ){
    System.out.println("Test(" +a +")");
    Test();//wont compile
  }
                                                                                
  public static void main(String args[]){
    Test t = new Test(22);
  }
}

Why does the call to Test() int the second ctor cause the compiler to complain? (cannot resolve symbol).

[chi Lin]

hi,
When call one constructor from another, you use this() or
this(necessary parameter), and it should be the first statement
inside the constructor.

[merlin bar]

Thats great, thanks!

[Gabriel White]

Now why doesn't this work?? It looks properly formatted besides the other constructor call not being the first statement.

public class Test
{
  public Test()
  {
    System.out.println("Test()");
  }
  public Test(int a)
  {
    Test t = new Test();//added this line is this what you are talking about?
    System.out.println("Test(" +a +")");
    //Test();//wont compile
  }
  public static void main(String args[])
  {
    Test t = new Test(22);
  }
}

[ December 15, 2003: Message edited by: Steve Wysocki ]

[Ernest Friedman-Hill]

"this" is a keyword. Use is like so:

public class Test {
  public Test() {
    System.out.println("Test()");
  }
  public Test(int a) {
    this(); // invoke the no-arg constructor
    System.out.println("Test(" +a +")");
  }
}

Note that a call to this(), if it appears, must be the first line in a constructor -- i.e., you can't print something first, then call this().
[/code]

[Gabriel White]

Thanks E, total brain fart on that one. I just didn't key in on the command that I have used before: this();. Sorry to waste your valuable brain cells on that one.
Thanks