Explain binding

[Oceana Wickramasinghe]

What exactly is binding in java? I've read about static binding and dynamic binding but i dont have a clear understanding of what binding really is. I want an easy to understand explanation. Thanks in advance

[Ernest Friedman-Hill]

It just refers to the process of matching up a method name in your source code to the actual method that gets executed at runtime. The rules for how this is accomplished are different for static methods, for final methods, for non-final methods, and for overloaded methods. "Early" or "static" binding basically means that the compiler can figure it out completely; "late" or "dynamic" binding means that the decision isn't made until runtime.

[Oceana Wickramasinghe]

Ernest Friedman-Hill wrote:It just refers to the process of matching up a method name in your source code to the actual method that gets executed at runtime. The rules for how this is accomplished are different for static methods, for final methods, for non-final methods, and for overloaded methods. "Early" or "static" binding basically means that the compiler can figure it out completely; "late" or "dynamic" binding means that the decision isn't made until runtime.

Thank you very much, but what if i called a static method using a reference variable? Would that still be static binding or dynamic binding?

[Ernest Friedman-Hill]

Oceana Wickramasinghe wrote:what if i called a static method using a reference variable? Would that still be static binding or dynamic binding?

Yes. The reference value is ignored -- it can even be null! All that matters is the declared type of that variable; the compiler uses that type, and only that type, to choose the static method. Static methods are never "overridden" -- there's no dynamic lookup, ever.

[Campbell Ritchie]

Which is why it is bad practice to call static members on an object reference. You should call static members on the name of the class.

[Jayavardhan geepi]

Just to add.

If you look at .class file using any java decompiler , you can see that compiler have had replaced object ref variable with type of that variable.