Functions

Expressions allow you to apply basic operations such as addition, division, and concatenation to operands, in order to produce a value. Often, however, you need to perform more complex operations in order to derive a value you need. Moreover, sometimes you need to obtain a value (today's date, for instance) which cannot be derived from the data within your test. Functions are prewritten operations which you can reference by name within your expressions to produce values needed by your test.