In Chapter 22, "Building User-Defined Functions," you learned how to create your own user-defined functions (UDFs). These are exciting because they allow you to add to the CFML language to better suit your needs. Once you have written a UDF, you can use it just like one of ColdFusion's own built-in functions. Extending ColdFusion's language lets you reuse your code in many different places. That makes your job easier and more productiveplus, it's fun!
Let's recap the four basic ways of extending ColdFusion: