有没有办法让PHP在比较不同类型时产生警告？

Question

I've inherited a large codebase that almost exclusively uses loose comparisons:

$foo = 1
$bar = "1"

if ($foo == $bar)
{
    doThing();
}

In some cases, this has led to bugs.

I know that I could switch all of the == operands to ===, but I'm afraid that that could cause new issues that remain unnoticed until the code gets pushed to the production environment. Obviously that would be very bad.

Is there some global setting that I can enable to make PHP produce warnings when comparing two different types?

Answer 1

No.

You might want to take a look at strict typing defined in the docs. But it's not exactly what you're looking for, unfortunately.

Since PHP introduced type declarations, you can make sure your methods are guaranteed to receive the parameter types requested. You may also declare the return type, which will also guarantee that your method returns the right type.

I am assuming you inherited a legacy codebase using PHP 5. Your only solution here would be to upgrade to PHP 7 (preferably 7.3) and refactor the methods.

On the other hand, you could also fork PHP source and write the necessary code yourself or even propose this to other PHP devs. But reviewing your proposal will probably take years.