optimization - Data verifications in Getter/Setter or elsewhere?

Question

I'm wondering if it's a good idea to make verifications in getters and setters, or elsewhere in the code.

This might surprise you be when it comes to optimizations and speeding up the code, I think you should not make verifications in getters and setters, but in the code where you're updating your files or database. Am I wrong?

Answer 1

Well, one of the reaons why classes usually contain private members with public getters/setters is exactly because they can verify data.

If you have a Number than can be between 1 and 100, i would definitely put something in the setter that validates that and then maybe throw an exception that is being caught by the code. The reason is simple: If you don't do it in the setter, you have to remember that 1 to 100 limitation every time you set it, which leads to duplicated code or when you forget it, it leads to an invalid state.

As for performance, i'm with Knuth here:

"We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil."