将变量添加到数组内的路径中

Is it possible to add a variable into the line in bold?

$opts = array(
    // 'debug' => true,
    'roots' => array(
        array(
            'driver'        => 'LocalFileSystem',   // driver for accessing file system (REQUIRED)
            **'path'          => '/csgo',         // path to files (REQUIRED)**
            'URL'           => dirname($_SERVER['PHP_SELF']) . '/../files/', // URL to files (REQUIRED)
            'accessControl' => 'access'             // disable and hide dot starting files (OPTIONAL)
        )
    )
);

changing it to this did not help

'path'          => ".$folder./csgo",         // path to files (REQUIRED)

thank you

It should be:

'path' => "$folder/csgo"

A slightly better way:

'path' => "{$folder}/csgo"

This clearly shows the separation of the variable from the string