Javascript verifies whether the URL address entered by the user is empty and the format is correct_javascript skills

Copy code The code is as follows:

Copy code The code is as follows:

URL:

PHP detects URL address validity

The code is as follows

Copy code The code is as follows:

function is_url($str){
return preg_match("/^http://[A-Za-z0-9] .[A-Za-z0-9] [/=?%-&_~`@[]': !]*([^< ;>"])*$/", $str);
}
?>

If you want to try if it works normally, we can use the file_get_contents() function to verify it.