Coverting an int to a different base. php, .NET

Hey I have seen sites that instead of an int show you a string.

For example d2fr4st == 147392525 and d2fr4ss == 147392524. What base is this? And how can I do the sa开发者_JAVA百科me conversion in php and .NET?

At the moment converting from 147392524 to d2fr4ss would be most useful.

For .Net there's an implementation here: base36

UInt64ToBase36(147392524); //2FR4SS
UInt64ToBase36(147392525); //2FR4ST

Like VolkerK said I'd assume the d is an identifier perhaps just to show that the string is a base36 number if it's using more bases.

echo base_convert(147392524 , 10, 36), "\n";

prints 2fr4ss. The leading d might be an identifier or some kind of checksum ...or simply a typo?

see http://docs.php.net/base_convert

It's probably base64. PHP has base64_encode, ASP.NET has Convert.ToBase64String