PHP return type

Question

Is it possible to define the return type like this?

public static function bool Test($value)
{
      return $value; //this value will be bool
}

Solution 1

As per this page : http://php.net/manual/en/language.types.type-juggling.php

You can try doing,

return (boolean) $value;

Now PHP offer return type declaration from PHP 7. I have explained how to use return type in PHP

Solution 2

Since this question still comes up in search engine results, here is an up-to-date answer:

PHP 7 actually introduced proper return types for functions / methods as per this RFC.

Here is the example from the manual linked above:

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

Or, in a more general notation:

function function_name(): return_type {
    // some code
    return $var // Has to be of type `return_type`
}

If the returned variable or value does not match the return type, PHP will implicitly convert it to that type. Alternatively, you can enable strict typing for the file via declare(strict_types=1);, in which case a type mismatch will lead to a TypeError Exception.

Easy as that. However, remember that you need to make sure that PHP 7 is available on both, your development and production server.

Solution 3

It's not possible to explicitly define the return type at the method/function level. As specified, you can cast in the return, so for example ...

return (bool)$value;

Alternatively, you can add a comment in phpDoc syntax, and many IDEs will pick up the type from a type completion perspective.

/**
 * example of basic @return usage
 * @return myObject
 */
function fred()
{
    return new myObject();
}

Solution 4

Return type added in PHP 7 ;)

https://wiki.php.net/rfc/return_types

Solution 5

Since PHP 7.0, you can declare the return type like this:

function returnABool(): bool {
    return false;
}

Not only common data types, you can return expected object instances as well. For example you expect a function to always return an instance of a class. This can be achieved like this:

class Biography {
    public function name() {
        return 'John Doe';
    }
}

Now you can declare the return type for this object like this:

function get_bio(): Biography {
    return new Biography();
}

When the function or method returns an unexpected data type, a TypeError is thrown. Here is an example where you will encounter a TypeError.

class Biography {
    public function name() {
        return 'John Doe';
    }
}

class Bio2 {
    public function name() {
        return 'John Doe';
    }
}

function get_bio(): Biography {
    return new Bio2;
}

And an example that will not throw any TypeError:

class Biography {
    public function name() {
        return 'John Doe';
    }
}

class Bio2 {
    public function name() {
        return new Biography();
    }
}

function get_bio(): Biography {
    $bio2 = new Bio2;
    return $bio2->name();
}

More details on declaring return data types for functions and methods can be learnt from the official documentation.

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