Advantage of "condition == $variable" style?

Question

I often see if's like:

if (null === $var)

I wanted to know wether there is any technical advantage by using it?

I find it semantically wrong and I don't like it. Prefer

if ($var === null)

because I ask for the condition of a variable, not for a variable having a condition.

i use $var === null .. both are correct, use the style you prefer — donald123, Jan 05 '15 at 09:05
If this is opinion based, well, would answer my question (no, no technical advantage). But why downvote... — Daniel W., Jan 05 '15 at 09:06
I think it stems from the practice of using non-lvalues on the left side of a == operator. If you accidentally use =, then most languages will throw an error about an invalid assignment, but you might miss it if the terms were switched. — Paul Dixon, Jan 05 '15 at 09:07
I admit this is not exactly easy to google for, but it has been asked countless times. Just follow the trail of dupe closes... — deceze, Jan 05 '15 at 09:08

score 1 · Accepted Answer · answered Jan 05 '15 at 09:06

This type of conditions is sometimes referred to as yoda conditions. Their main advantage is that they avoid accidental assignment:

if ($foo = 'bar')
    echo 'Evaluates to true, and reassigns $foo silently';
if ('bar' = $foo)//error

Other than that, it's a matter of personal preference

1 Answers1