Pre-declare all private/local variables?

Question

This may be a basic question, but it has kept me wondering for quite some time now.

Should I declare all private/local variables being private? Or is this only neces

Answer 1

In most if not all cases: yes.

If the variables are class properties they absolutely should be declared before use.

If the variable is local to a function, declare it in that function before you use it. Function variables are confined to the function's scope (local variables). They don't have to be declared before use but it's good practice to do so, and it gets rid of a warning message if you do. If they are not used anywhere else, they should not be properties though,