致命错误：使用array_walk在不在对象上下文中时使用$ this

Question

I have made a class that should replace data at the hand of an array.

I insert

$data = array(
                'bike',
                'car',
                'pc'
            );

And it should translate the array to :

$data = array(
                '[@bike]',
                '[@car]',
                '[@pc]'
            );

I have written the following piece of code.

array_walk($PlaceHolders , function(&$value, $key) { $value = $this->Seperators['plcstart'].$value.$this->Seperators['plcend']; });

Which I am using in a class context.

The two sperators have the following value:

$this->Seperators['plcstart'] = '[@';
$this->Seperators['plcend']   = ']';

The problem is. At localhost it works superb!! Now when I upload the system to a unix environment it stops working! I have no clue why this is the result.

Would anyone here know what I am doing wrong?

Answer 1

I would recommend you to use array_map() when you want to modify array elements using a callback.

You could end with something like this

class TransformerClass {
    private $Seperators = array(
        'plcstart' => '[@',
        'plcend' => ']'
    );

    public function transform(array $data) {
        return array_map(
            function($text) {
                return $this->Seperators['plcstart'].$text.$this->Seperators['plcend'];
            },
            $data
        );
    }
}

Example:

$transformer = new TransformerClass();

$items = array(
    'bike',
    'car',
    'pc'
);

$result = $transformer->transform($items);

And $result will contain your desired resulting data.