error with using variables as associative array value in php - php

Question

For some reason this is giving me the follow error: syntax error, unexpected T_VARIABLE:
$mysql = json_decode(getenv("VCAP_SERVICES"));
$mysql = $mysql["mysql-5.1"][0]["credentials"];
class DATABASE_CONFIG {
public $default = array(
'datasource' => 'Database/Mysql',
'persistent' => false,
'host' => 'localhost',
'port' => $mysql['port'], // <-- Line with error
'login' => $mysql['username'],
'password' => $mysql['password'],
'database' => $mysql['name'],
'prefix' => ''
//'encoding' => 'utf8',
);
public $test = array(
'datasource' => 'Database/Mysql',
'persistent' => false,
'host' => 'localhost',
'login' => 'user',
'password' => 'password',
'database' => 'test_database_name',
'prefix' => '',
//'encoding' => 'utf8',
);
}
I know you can use variables as values in arrays, so what is going on?

Answer 1

It looks like you're trying to set the default value of a property to a variable.
You can't do that, not even inside an array. This is half PHP's parser sucking, a quarter of PHP's lack of appropriate error message, and a bit of sanity.
You'll need to do it from within the constructor instead by passing in $mysql:
$config = new DATABASE_CONFIG($mysql);
class DATABASE_CONFIG {
public $default = array(
'datasource' => 'Database/Mysql',
'persistent' => false,
'host' => 'localhost',
'port' => null,
'login' => null,
'password' => null,
'database' => null,
'prefix' => ''
//'encoding' => 'utf8',
);
public function __construct($mysql) {
$this->default['port'] = $mysql['port']; // etc
}
}

Answer 2

$mysql has no scope inside the class.
You need to inject it as an argument into the class constructor, and then define your array values for the class properties

Answer 3

You're trying to reference a variable inside a class which is defined outside of that class.
PHP has no idea what $mysql is inside of that class definition.