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phpooptestingstaticstatic-variables
onin
onin

Reputation: 5760

Static variable in method doesn't reset on instance unset

Interesting behavior in PHP 5.6.12-arm and PHP 7 RC3 (though I guess it's like that in all version, I just wanted to note which versions I've used to test):

Example - using a static variable inside class method

<?php
class Foo {
    public function Bar() {
        static $var = 0;

        return ++$var;
    }
}

$Foo_instance = new Foo;

print $Foo_instance->Bar(); // prints 1
print PHP_EOL;

unset($Foo_instance);

$Foo_instance2 = new Foo;

print $Foo_instance2->Bar(); // prints 2 - but why?
print PHP_EOL;
?>

Question: How can a 2 be printed, since we unseted the whole instance before calling Foo->Bar() again?

Please note that this question and its answers don't answer my question.

Best regards.

Upvotes: 1

Views: 182

Answers (1)

Federkun
Federkun

Reputation: 36944

You can look in the php documentation of variables scope.

if you declare a variable as static inside a function, it's static for the whole class and all of its instances, not for each object.

So, a static variable is not related to a single instance.

Upvotes: 1

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