将变量传递给file_get_html在Simple DOM中不起作用

Question

I have a code here describing the problem, I need to run file_get_html() at my variables, the valid argument must have 'http://google.com' my variable starts at domain only -> add the http:// and /, but at you can see it doesn't work, it ends giving:

Warning: file_get_contents('http://google.com/'): failed to open stream: Invalid argument ... simple_html_dom.php on line 75

here is the code

        require_once('/simplehtmldom_1_5/simple_html_dom.php');
        $a = 'google.com';                              //from domain only: google.com
        $b = "'http://" . $a . "/'";                    //then, modify to have this form: http://google.com/
        //$html = file_get_html($b);                    //this thing doesn't work
        $html = file_get_html('http://google.com/');    // but this thing works

Answer 1

In your code the final contents of $b contain single quotes which aren't necessary if you're handling variables.

Change this line to remove the single quotes

 $b = "'http://" . $a . "/'";  
       ^                  ^  Remove these.