Function Outside the Class

[Amal Gupta Java Guy]

Is it possible to write a java function outside the class?
Let me illustrate here:
ex:
class test
{
int a,b;
boolean equals(Test o)
{
//body of equals
}
}
here definition of fun equals is written inside the class test.
Ques --- but i want to write the definition of fun equals outside the class
becos it's very long.
How can i do this.
in c++ i can write
class test
{
int a,b;
boolean equals(Tet o);
}//end of class test
boolean test::equals()
{
body of fun
} :roll:

[Vijayakumar Arya]

Hi,
Java didnot allow such conventions. You have to declare all the methods within the same class definition.
Also you cannot have a free floating function - global function as in c++, in Java, even for a static method it should be contained in a class.

[Robert Paris]

well...not totally. You can't do it at compile time, but you can do it on the fly. You can add bytes to a class on the fly. If you know the Java Virtual machine spec, you can do it, but i think you might also be able to do it with Apache's BCEL: http://jakarta.apache.org/bcel/index.html
Not exactly the same as what you're thinking of in C++, but pretty close. There are also other options. Make your class abstract, and don't implement that method. make an interface. But, yeah, you could create the byte-code for a method and tie it to a class at runtime.

[Vijayakumar Arya]

Hi Robert,
The argument is that whether the Java as a language supports such as feature and not whether there is an alternate way to acheive that.
Please don't scare me by saying some bytecode can be attached at runtime.

[Cindy Glass]

Amal Gupta Java Guy,
Please change your name to be compliant with JavaRanch's naming policy.
Your displayed name should be 2 separate names with more than 1 letter each and not be OBVIOSLY FICTICIOUS. We really would prefer that you use your REAL name.
You can change your name: here.
Thanks,
Cindy

[Robert Paris]

Vijayakumar,
1. I'm not scaring you, it's a great feature!
2. The addition of bytecode IS the java language.
The Java language/runtime allows this and has it as a part of its features. It's a great thing, and frankly I don't see how your C++ version is any less scary or insecure as adding bytecode. Why can't I come in with my own C++ class in the same namespace and make an implementation of this method?

[Bear Bibeault]

Before resorting to something like that, why do you feel you need to have a function outside of a class?
I'm sure that there is a simple design solution that doesn't involve scary features.
hth,
bear