How to optimize numerous 'else if'?

Question

There are data from the user that I need to check for membership in a particular range, and depending on this output a different result. I use this method:

if($var < 1000) {
    do one
}
else if ($var < 2000) {
    do two
}
else if ($var < 3000) {
    do three
}
....

But it looks unprofessional. How can I optimize this code? /without 'switch' - it's almost the same/

you can use a ternary operator. depending on how many statements you have though, it might become unreadable. here's a [blog post](https://davidwalsh.name/php-shorthand-if-else-ternary-operators) — the holla, Feb 09 '17 at 11:48
@DianaHolland: Not the PHP ternary conditional! They reversed the associativity of the operator. Why?! — Bathsheba, Feb 09 '17 at 11:53
@Bathsheba whoa. (more explanation [here](http://stackoverflow.com/questions/20559150/ternary-operator-left-associativity)) — the holla, Feb 09 '17 at 18:18
Wonderful, isn't it. I wouldn't buy a driverless car whose software was written in PHP. — Bathsheba, Feb 09 '17 at 18:22

score 2 · Answer 1 · answered Feb 09 '17 at 11:48

Looks fine to me:

It's readable.
It's unlikely to be a performance bottleneck.

Don't overthink this. You could probably massage the whole thing into a table of functions keyed by ranges, but why obfuscate what is clear and simple?

Don't use a chain of ternary conditional operators since, for some reason, the PHP folk decided to fiddle around with the associativity of that operator cf. C, C++, and Java.

OllyBarca · Answer 2 · 2017-02-09T11:58:52.977

I guess it depends on the logic inside each if - else block. If it is just returning, or calling a method for example, you could do the following:

if ($var < 1000) return 1;
if ($var < 2000) return 2;
if ($var < 3000) return 3;

If the logic inside each condition is more than one operation, you could move it to a function and simple call the relevent function.

To be honest, what you have is fine. As long as it is clean and readable. You should only start worrying about cleanliness when they become more nested.

How to optimize numerous 'else if'?

2 Answers2