| 
 •   | 
 api—an instance of the API that you selected in the Type box, such as HitAnalysis. The api variable provides access to traffic analysis data as well as to other key functionality such as regular expressions.   | 
| 
 •   | 
 results—a collection used to store the values for the output variables (defined in the Output Variables pane). Data generated by the script is put into the results collection through an assignment statement, such as results.outputVariable = someValue.  | 
| 
 •   | 
| 
 •   | 
 Generate and cache values for the script’s output variables using the results collection. The values can be used by analyzers in match conditions, custom fields, and metrics.  | 
| 
 •   | 
 Use return statements to exit silently whenever a script cannot access data or meet some other precondition it needs to proceed. When a script quits, any unset output variables continue to be undefined (null) values. Exiting a script through a return statement does not count as an uncaught failure.  | 
| 
 •   | 
 Add regular expressions to your script to do things like match a pattern. You can create and test regular expressions in the Extraction Rule tool by clicking Regular Expression Tester. For more information, see Testing regular expressions.  | 
| 
 •   | 
 Check your syntax while you work by clicking Check Syntax. The Syntax Messages box displays errors or warnings regarding basic syntactical errors. Security violations or references to undefined classes or methods are not detected or reported.  |