php类中的变量内的变量

Question

is it possible to copy a variable like this this?

class Colours {
   var $var = "one";
   var $var2 = array('something', $var);
}

Answer 1

The preferable way is to do this in the constructor of the Colours class. I'm not sure in PHP, but in other languages the order of initialisation of the variables should not be relied upon.

class Colours 
{ 
    private $var;
    private $var2;

    public function __construct()
    {
        $this->var = "one";
        $this->var2 = array('something', $this->var);
    }
}

Answer 2

You'd need to use $this->var to access the variable

class Colours {
   var $var = "one";
   var $var2 = array('something', $this->var);
}

Answer 3

 <?php
     $var = "one";
     $var2 = array('something', $var);
    print_r($var2)
    ?>


 I got the following output 



     Array 
    (
            [0] => something
            [1] => one
    )