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Comment by ccoggins | Hacker News Reader

Yeah, they can be tricky to read sometime. The only reason I've ever heard for writing code like that is to prevent accidental assigning in an if block. For instance if(ptr = 0) compiles fine in C and is almost certainly not what you want, but if(0 = ptr) is a compile error.

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Sadly, I've seen them in other languages that don't have the same problem, because people have picked up the habit without really understanding why and where it should be used.

Unfortunately they are becoming more and more prevalent in the PHP community. For example, here they are in the Symfony project's coding standards: http://symfony.com/doc/current/contributing/code/standards.h...

The rationale is that they make it a compiler error if you accidentally perform an assignment operation ("xyz" = $name) instead of a comparison ("xyz" === $name). The thing is, this is only a significant risk if you adopt the bad habit of performing assignment operations within conditional statements, like this:

    if (null !== ($charset = $env->getCharset())) {

The above style has been popularised in PHP by the Symfony project. I think it's hideous, and that the idea of adopting one ugly style choice (Yoda Expressions) to mitigate the risk introduced by another ugly style choice (assignment in conditional operations) is reminiscent of the children's song about the old lady who swallowed a fly.

I used to advocate for Yoda in PHP for the same reason that it's useful in C:

   if ($var = 1) ...

will always evaluate true.

But since you should be using === in this context, there's really no excuse for using a single...

    if ($var === 1) ...

Also, can PHP devs please do me the favor of splitting

    if (null !== ($charset = $env->getCharset())) {

into two lines:

    $charset = $env->getCharset();
    if ($charset !== null) {
    ...

Isn't that prettier? The line that the first one saves doesn't really make anyone's life easier...

Huh? You might still mistype/forget an =, even if you never intend to perform assignment in a conditional. You never have to do it on purpose to do it by mistake, in other words.

That was indeed the rationale when they first appeared.

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