I finally decided to write up a little something about Java's parameter passing.I keep on hearing from my friends and even my tutors that "primitives are passed by value, objects are passed by reference".

Pass-by-value
The actual parameter (or argument expression) is fully evaluated and the resulting value is copied into a location being used to hold the formal parameter's value during method/function execution. That location is typically a chunk of memory on the runtime stack for the application (which is how Java handles it), but other languages could choose parameter storage differently.

Pass-by-reference
The formal parameter merely acts as an alias for the actual parameter. Anytime the method/function uses the formal parameter (for reading or writing), it is actually using the actual parameter.

Java is strictly pass-by-value.When the method or constructor is invoked (�15.12), the values of the actual argument expressions initialize newly created parameter variables, each of the declared Type, before execution of the body of the method or constructor. The Identifier that appears in the DeclaratorId may be used as a simple name in the body of the method or constructor to refer to the formal parameter.