Monday, January 04, 2010

Use of Overriding Methods Considered Harmful

I've come to the conclusion that overriding methods is a bad idea.

You know the situation; you've subclassed another class, which has a method in it that's not quite perfect, so in your subclass you write another method (giving it the same parameters) that does something slightly different.

Cue several months later, and you innocently edit the method in the parent class, changing the method parameters. Suddenly bugs appear left right and centre. "But how?" you ask yourself.

Well, it's because the method in the subclass is now never called since the method signature is different to the parents signature. But how were you supposed to know? Exactly!!

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