在 class PHP 中使用主文件的变量

Question

i have a main php file which contains the variable:

$data['username']

which returns the username string correctly. In this main file i included a class php file with:

require_once('class.php');

they seem linked together well. My question is: how can I use the $data['username'] value inside the class file? I'd need to do an if statement to check its value inside that class.

class.php

<?php

class myClass {
    function __construct() {

        if ( $data['username'] == 'johndoe'){   //$data['username'] is null here
          $this->data = 'YES';
        }else{
          $this->data = 'NO';
        }
    }
}

Answer 1

There are many ways to do that, we could give you accurate answer if we knew how your main php file and the class look like. One way of doing it, from the top of my head:

// main.php
// Instantiate the class and set it's property
require_once('class.php');
$class = new myClass();
$class->username = $data['username'];

// Class.php
// In the class file you need to have a method
// that checks your username (might look different in your class):
class myClass {

    public $username = '';

    public function __construct() {}

    public function check_username() {
        if($this->username == 'yourvalue') {
            return 'Username is correct!';
        }
        else {
            return 'Username is invalid.';
        }
    }
}

// main.php
if($class->username == 'yourvalue') {
    echo 'Username is correct!';
}

// or
echo $class->check_username();

Answer 2

If the variable is defined before the call to require_once then you could access it with the global keyword.

main.php

<?php
$data = [];
require_once('class.php');

class.php

<?php
global $data;

...

If your class.php is defining an actual class then I would recommend Lukasz answer.

Based on your update I would add the data as a parameter in the constructor and pass it in on instantiation:

<?php
require_once('class.php');

$data = [];

new myClass($data);

Adjusting your constructor to have the signature __construct(array $data)