About Question enthuware.ocajp.i.v7.2.947 :

[The_Nick]

Hi,
I thought that it was line 4 as even though the "x" and "y" variables are not initialized (hence the code will not compile), as a constructor should be consider valid. No?
It cannot start with a tilde? I don't see why it's not a valid constructor besides the fact that does not compile.

Thanks in advance.

[admin]

You can't start a method or constructor with ~. It will not compile because of that as well.

[The_Nick]

So making a recap, to be a correct identifier it must be of a range of letter [A-Z] [a-z] digits [0-9]. It must not begin with a digit. $ and _ are also valid character.
That's what I found on line. But I also noticed that an identifier as int £34$_ =10; works well.

Does it mean that any currency symbol can be used in an identifier?

Thanks in advance.


The_Nick

[admin]

You may want to check this out: http://docs.oracle.com/javase/specs/jls ... ml#jls-3.8

[swziy123]

Question is "Which line contains a valid constructor in the following class definition?"

and line:
public TestClass getInstance() { return new TestClass(); }

CONTAINS valid constructor, because new TestClass() is a valid default constructor. Question sentence is misleading.

[admin]

The sentence is correct. new TestClass(); is not a constructor, it is an invocation of a constructor.