CODEWITHSUNDEEP
phplambdafunctional-programmingphp-7
Itay Moav -Malimovka
Itay Moav -Malimovka

Reputation: 53607

making a class's static-member a function (closure) does not work

(PHP7) Consider the following code, which tries to assign a function to a variable, and then make sure it is called only once. 

class a{
  static public $b;
  static public function init(){
     self::$b();
     self::$b=function(){};
  }
}
a::$b=function(){echo 'Here I do very heavy stuff, but will happen only in the first time I call init()';};

for($i=0;$i<1000;$i++){
   a::init();
}

In php7 it will give an error that it expects a::$b to be a string (the function name to call).
If I use pure variables and not static members, it will work.
My question, is this suppose to work, or not, or is there a small tweak I can do for this to work without pure vars?

Upvotes: 4

Views: 63

Answers (1)

bishop
bishop

Reputation: 39434

You can either use PHP 7 Uniform Variable Syntax:

(self::$b)();

Or a temporary variable in PHP 5+ (including 7):

$init = self::$b;
$init();

As seen on 3v4l.org.

Upvotes: 5

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