PHP唯一的变量应该通过引用传递

I was setting up a PHP server when this error came up:

Strict Standards: Only variables should be passed by reference in C:\xamp\htdocs\Xce Source\Source\Extra\Xce.php on line 75 PHP Strict Standards: Only variables should be passed by reference in C:\xamp\htdocs\Xce Source\Source\Extra\Xce.php on line 75

This is the line 75:

$ready = socket_select($read, $w = null, $e = null, $t = 0);

What do I need to change? I always have this problem with exactly this same code

Instead of $ready = socket_select($read, $w = null, $e = null, $t = 0); use this:

$w = null;
$e = null;
$t = 0;

$ready = socket_select($read, $w, $e, $t);

When you do something like this $w = null as a function parameter, you are actually passing null, not a reference to the $w variable. socket_select requires references as parameters to work.

As said in the documentation there, it should be:

$w = null; 
$e = null; 
$t = 0; 
$ready = socket_select($read, $w, $e, $t)