Java is Pass-by-Value, Dammit! | JavaDude.com

I finally decided to write up a little something about Java’s parameter passing. I’m really tired of hearing folks (incorrectly) state “primitives are passed by value, objects are passed by reference”. I’m a compiler guy at heart. The terms “pass-by-value” semantics and “pass-by-reference” semantics have very precise definitions, and they’re often horribly abused when folks talk about Java. I want to correct that… The following is how I’d describe these 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. 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 actual

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• Osher Lerner