What is the benefit of using multiple steps to complete an if test?

Question

What is the benefit of using multiple steps to test variables:

$VarLength = strlen($message);
if ($VarLength > 10)
    echo "Over Ten";

...versus just pushing the whole process into one if statement:

if ( strlen($message) > 10 )
    echo "Over Ten";

I'm wondering if the benefits go beyond code style, and the ability to re-use the results of the (in the example above) strlen result.

Answer 1

Your question is not really possible to answer technically, so this is more a comment than an answer.

Benefits beyond code-style and re-use of the result is when you change the code.

You might want to replace the strlen() function with some other function but you don't want to edit the line with the if clause while you do so. E.g. to prevent errors or side-effects. That could be a benefit, however it depends on code-style somehow. So as you exclude coding style from your question, it makes it hard to answer as that domain touches a lot how you can/should/would/want/must write code.

Answer 2

If the result of a function will be used multiple times, it should be cached in a variable so as to obviate the need to waste resources to re-calculate its result.

If the function result won't be re-used, it can simply be a matter of code readability to clearly delineate what's happening by storing the function return value in a variable before using it in an if condition.

Also, in terms of readability, you should always use curly braces even when not mandated by PHP syntax rules as @AlexHowansky mentions.