PHP：使用preg_match获取url变量？

Question

http://www.example.com?id=05

or

http://www.example.com?id=05&name=johnny

This is a string. And I want to get the value of $id from it.

What is the correct pattern for it?

Answer 1

You don't need regex (and you shouldn't be jumping straight to regex in the future unless you have a good reason).

Use parse_url() with PHP_URL_QUERY , which retrieves the querystring. Then pair this with parse_str() .

$querystring = parse_url('http://www.mysite.com?id=05&name=johnny', PHP_URL_QUERY);
parse_str($querystring, $vars);

echo $var['id'];

Answer 2

@PhpMyCoder's solution is perfect. But if you absolutely need to use preg_match (though completely unnecessary in this case)

$subject = "http://www.mysite.com?id=05&name=johnny";
$pattern = '/id=[0-9A-Za-z]*/'; //$pattern = '/id=[0-9]*/'; if it is only numeric.
preg_match($pattern, $subject, $matches);
print_r($matches);