Is it better to wrap code into an 'IF' statement, or is it better to 'short circuit' the function and return? [closed]

Answer 1

The first one is usually preferred simply because it reduces the needed indentation (which could get way out of hand). There is no real performance difference.

Answer 2

FWIW, I'll offer a contrary opinion. Structured Programming suggests that a function should have one point of exit. I think there are some compiler optimizations that are not available if you use early returns, break statements, goto statements and the like. Also more branches in your code means its harder to fill the CPU pipeline resulting in a possible performance reduction... There are also reasons for not returning early that deal with rigorous (i.e. algebreic) reasoning about correctness.

Structured Programming wiki article

Answer 3

It really depends. I do like one point of return for simple functions, but anything longer than 10-20 lines and I'll start breaking things up for the sake of code clarity.

Answer 4

There are some people who think that each function should have a single exit point. However, I find it clearer when quick conditional checks like the one you mentioned are done at the beginning. It also avoid some code from being unnecessarily run.

Answer 5

If there are multiple / complex guards, I would use the return. Otherwise in the case of one simple condition (in a smallish function) then I prefer using an if.

Answer 6

Usually I have input-validation return right away. Imagine if you had a bunch of conditionals, you'd get a mess of nested ifs right away.

Generally once I get past input validation I avoid multiple returns, but for validation I return right away. Keeps it cleaner IMHO.