CODEWITHSUNDEEP
php-7
Derrek Bertrand
Derrek Bertrand

Reputation: 626

PHP 7: use both strict and non-strict type hinting?

So PHP 7 has scalar type hinting now (w00t!), and you can have the type hints be strict or non-strict depending on a setting in PHP. Laracasts set this using define, IIRC.

Is there a way to have strict type hinting on scalars in one file (like a math library) while at the same time using non-strict elsewhere WITHOUT just arbitrarily changing settings in your code?

I'd like to avoid introducing bugs by not fidgeting with the language settings, but I like this idea.

Upvotes: 1

Views: 1303

Answers (1)

mystery
mystery

Reputation: 19533

Indeed, you can mix and match to your heart's content, in fact the feature was specifically designed to work that way.

declare(strict_types=1); isn't a language setting or configuration option, it's a special per-file declaration, a bit like namespace ...;. It only applies to the files you use it in, it won't affect other files.

So, for example:

<?php // math.php

declare(strict_types=1); // strict typing

function add(float $a, float $b): float {
    return $a + $b;
}

// this file uses strict typing, so this won't work:
add("1", "2");

<?php // some_other_file.php

// note the absence of a strict typing declaration

require_once "math.php";

// this file uses weak typing, so this _does_ work:
add("1", "2");

Return typing works the same way. declare(strict_types=1); applies to function calls (NOT declarations) and return statements within a file. If you don't have a declare(strict_types=1); statement, the file uses "weak typing" mode.

Upvotes: 5

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