为什么这不适用于生产[重复]

Question

This question already has an answer here:

• Can't use method return value in write context 7 answers

I have a really simple line of code:

if(empty(trim($this->name)) {
    $this->error = "Name required";
    return false;
}

This code works splendidly on my development environment, but throws a fatal error in production:

Can't use function return value in write context

Why is this, and more importantly, what do I need to change in my development environment so that my code behaves the same (aka breaks) on the development environment and in production?

Many thanks.

</div>

Answer 1

In versions of PHP below 5.5 you can not use the return value of a function or method with empty(). You have to do a "hack".

// Do only if your PHP version is lower than 5.5
$trimmedVal = trim($this->name);

if(empty($trimmedVal)) {
    $this->error = "Name required";
    return false;
}