Sams Teach Yourself PHP in 24 Hours, Third Edition

Creating a Query String

To create a query string, you need to be able to URL encode the keys and values you want to include. Assume that we want to pass a URL to another page as part of a query string. The forward slashes and the colon in a full URL would create ambiguity for a parser. We must therefore convert the URL into hexadecimal characters. We can do this using PHP’s urlencode() function, which accepts a string and returns an encoded copy:

print urlencode("http://p24.corrosive.co.uk");
// prints http%3A%2F%2Fp24.corrosive.co.uk

Now that you can URL encode text, you can build your own query string. The following fragment builds a query string from two variables:

 <?php $interest = "arts"; $homepage = "http://p24.corrosive.co.uk"; $query ...