Question

I would like to bind a variable to a function’s scope, I can do this in php use the ‘use’ keyword after PHP 5.3, however how do I do the equivalent in versions < PHP 5.3?

  test_use_keyword();
  function test_use_keyword(){
    $test =2;
    $res=array_map(
      function($el) use ($test){
        return $el * $test;
      }, 
      array(3)
    );
    print_r($res); 
  }

Answer 1

You can use a global variable, but you should always avoid globals variables whereever possible. As a suggestion, without knowing, what you are trying to solve with this

class Xy ( {
  private $test;
  public function __construct ($test) {
    $this->test = $test;
  }
  public function call ($el) {
    return $el * $this->test;
  }
}

print_r(array_map(array(new Xy(2), 'call'), array(3));

Also possible are the good old lambdas

$test = 2;
$a = create_function ('$el', 'return $el * ' . $test . ';');
print_r (array_map($a, array(3)));