如何在創建類之前定義變量？

Question

如何在初始化類之前或初始化時定義變量？

<?php
class class{
 public $var;
 public function __construct(){
  echo $this -> var;
 }
}
$class = new class;
$class -> var = "var";
?>

Answer 1

如果您的意思是實例化該類，那么使用構造函數：

class Foo {

    private $_bar;

    public function __construct($value) {
        $this->_bar = $value;
    }

}

$test = new Foo('Mark');

Answer 2

您可以通過兩種方式完成 - 請參閱此示例：

class bla {
  public static $yourVar;

  public function __construct($var) {
    self::yourVar = $var
  }
}

// you can set it like this without instantiating the class
bla::$yourVar = "lala";

// or pass it to the constructor while it's instantiating
$b = new bla("lala");

第一部分只能用靜態做，但如果你不想使用靜態，你必須通過構造函數初始化它。

希望這就是你要找的......

Answer 3

$myVariable; // variable is defined

$myVariable = new myClass(); // instance of a class

Answer 4

class myClass {
    protected $theVariable;

    protected function myClass($value) {
        $this->$theVariable = $value;
    }
}


$theVariable = 'The Value';

$theClass = new myClass($theVariable);

echo $theClass->theVariable;