PHP如何在另一个类中使用变量

Question

Iam learning php these days. I have one query below:

class A {

var $a;

}

class B extends A{

var $b = $a; //here its showing me error, i even tried as '$this->$a' but still showing error. so, how do I use $a in class B? ( instead of using in a function ), 

}

I am declaring $b just inside class instead of inside a function because I need to use $b variable in many places inside my php file.

So, please tell me how to fix this.

Answer 1

try like below

<?php

class firstname 
{
   public static $name='Your First Name';
}
class lastname
{
   public static $last='Your Last Name';
}
class Fullname
{

     public static function staticValue() {
        return firstname::$name."--".lastname::$last;
    }
}

print Fullname::staticValue() . "\n";
?>

hope it will help you

Answer 2

1.) use public instead of var 2.) when you extending a class, you have got access to properties of this parent. So you don't need to declare $b, you can just use $this->a

class a {
    $a = 'test';
}

class b extends a {
   public function get() {
       echo $this->a;
   }
}

$b = new b;
$b->get(); // prints test