Bad practice to use Variable functions?

Ok, really simple question - is it bad practice to use Variable functions in php?

I have a validator class that can use these and it makes sense to me but it does seem like it may be bad practice to do this?

EDIT: I can see that this there is going to be a lot of different opinions on this. Maybe if i explain how i intend to use them:

I have a base validator class with a method per field that i want to validate. I then have a classes that extend this base class and actually do the validating based on whatever logic i need. I have therfore called the methods in the base开发者_运维知识库 class after the fields they will validate. In the sub classes i can then simply loop through an array of required fields (whose keys match the field names also) and then simple call that function.

It seems really nice and clean but part of me keeps thinking its wrong.

EDIT: Where did those answers disapear to?

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No, it's not bad practice. Variable functions exist for a reason. They are what other languages term callbacks, or function pointers; Used all the time for a variety of applications.

I can't judge your specific use case since you provide no code, but I don't think you can go very wrong here. At worst, you can degrade performance slightly with unnecessary function calls. At best, you're using them exactly as intended.