How to check for equals? (0 == i) or (i == 0) [closed]

Answer 1

Maybe not an answer to your question. I try to use === (checking for identical) instead of equality. This way no type conversion is done and it forces the programmer do make sure the right type is passed,

Answer 2

I'm trying always use 1st case (0==i), and this saved my life a few times!

Answer 3

I use (i == 0) for the simple reason that it reads better. It makes a very smooth flow in my head. When you read through the code back to yourself for debugging or other purposes, it simply flows like reading a book and just makes more sense.

Answer 4

Code readability is one of the most important things for code larger than a few hundred lines, and definitely i == 0 reads much easier than the reverse

Answer 5

I always go with the second method. In C#, writing

if (i = 0) {
}

results in a compiler error (cannot convert int to bool) anyway, so that you could make a mistake is not actually an issue. If you test a bool, the compiler is still issuing a warning and you shouldn't compare a bool to true or false. Now you know why.

Answer 6

I used to be convinced that the more readable option (i == 0) was the better way to go with.

Then we had a production bug slip through (not mine thankfully), where the problem was a ($var = SOME_CONSTANT) type bug. Clients started getting email that was meant for other clients. Sensitive type data as well.

You can argue that Q/A should have caught it, but they didn't, that's a different story.

Since that day I've always pushed for the (0 == i) version. It basically removes the problem. It feels unnatural, so you pay attention, so you don't make the mistake. There's simply no way to get it wrong here.

It's also a lot easier to catch that someone didn't reverse the if statement in a code review than it is that someone accidentally assigned a value in an if. If the format is part of the coding standards, people look for it. People don't typically debug code during code reviews, and the eye seems to scan over a (i = 0) vs an (i == 0).

I'm also a much bigger fan of the java "Constant String".equals(dynamicString), no null pointer exceptions is a good thing.