Why doesn't the following code produce syntax errors?

[Tarun Mohandas]

I read constructors are not supposed to have return types. But when I compile the following code it compiles fine.

public class SomeClass {
public SomeClass(int i, float f) { }
public SomeClass(float f, int i) { }
public SomeClass(float f) { }
public void SomeClass() { }
}

How does the constructor have return types? How does this code work at compilation time and runtime (if we add a main method)? Can anyone walk me through the compilation please?

[Bill Gorder]

http://docs.oracle.com/javase/specs/jls/se7/html/jls-8.html#jls-8.8

The SimpleTypeName in the ConstructorDeclarator must be the simple name of the class that contains the constructor declaration; otherwise a compile-time error occurs.

In all other respects, the constructor declaration looks just like a method declaration that has no result type.

If it has a return type it is not a constructor.

I am moving this to the Beginning Java forum for you.

[Tarun Mohandas]

The SimpleTypeName in the ConstructorDeclarator must be the simple name of the class that contains the constructor declaration; otherwise a compile-time error occurs.

Could you please give me an example of declaration that causes a compiler error?

[Bear Bibeault]

Simply change the name of one of the constructors to something other than the class name.

[Tarun Mohandas]

Bear Bibeault wrote:Simply change the name of one of the constructors to something other than the class name.

But that becomes another method in that class. How does that produce compile time error?

[Paul Clapham]

I assume that means you didn't try it. Take a minute or two, try it, and see what happens.

[Bill Gorder]

    public class SomeClass {  
    public SomeClass(int i, float f) { }   //constructor there is no return type
    public SomeClass(float f, int i) { }  //constructor there is no return type
    public SomeClass(float f) { }  // constructor there is no return type
    public void SomeClass() { }  /* method there is a return type. 
 (this would be breaking naming conventions but that does not result in a compilation error)*/
    }  

If you change any of the constructors to have something other than the class name it will result in a compilation error.

[Tarun Mohandas]

Thank You all! I understood. It is just another method in the class if it has a return type.

That was very helpful. Thanks all