### 1.2 Flow Control Statements ¶

Almost everything you type at Yorick during an interactive session will be one of the simple Yorick statements described in the previous section – defining variables, invoking procedures, and printing expressions. However, in order to actually use Yorick you need to write your own functions and procedures. You can do this by typing Yorick statements at the keyboard, but you should usually put function definitions in a text file. Suggestions for how to organize such “include” files will be the topic of the next section. This section introduces the Yorick statements which define functions, conditionals, and loops.