Strange issue about # in url

http://localhost/t开发者_C百科est/editformquestions.php#?formid=1

And

http://localhost/test/editformquestions.php?formid=1

I failed to retrieve $_GET['formid'] in the first one,why?

The content of test/editformquestions.php is simply:

<?php

echo $_GET['formid'];
?>

Characters after the hash # are to be used by the browser, they are not sent back to the server.

# is a hash character, not a GET variable.

You need to put the ? before any hashes, otherwise the $_GET array will not be populated.

# is used by the browser, and is never sent to the server. Everything after a # (regardless of what it is) is used by the browser to jump to a location on the page.

So:

http://localhost/test/editformquestions.php#?formid=1

Will be split as follows:

• Server request to http://localhost/test/editformquestions.php

• Browser then searches in page for:

  <a name="?formid=1">named anchor tag</a>
  

What you should do is:

http://localhost/test/editformquestions.php?formid=1&othervar=2#anchorinpage

Or, if you need the # in a query-string parameter:

http://localhost/test/editformquestions.php?formid=1&othervar=textwith%23init

The # is fragment identifier for a URL: http://en.wikipedia.org/wiki/Fragment_identifier

To use it as part of an array variable you'll need to url encode it:

'#' becomes '%23' when url-encoded

In javascript you can accomplish url encoding with the encodeURI() function

A HTTP URL may contain these parts:

• protocol: http://
• domain: localhost
• path: /test/editformquestions.php
• query string: ?formid=1 - always starts with a ?
• fragment: #something - always starts with a # - whatever comes after the # mark is NOT sent to the server.

What you have in your first example (http://localhost/test/editformquestions.php#?formid=1) is a fragment containing this: #?formid=1. It does not matter that there's a ? in the fragment; as soon as it's behind the #, it is not sent from the browser.

So, in essence, you are sending to the server only this: http://localhost/test/editformquestions.php - as you can see, there is no formid in that request.