Inside Macintosh: AppleScript Language Guide / Part 2 - AppleScript Language Reference

Chapter 6 - Expressions

Results of Expressions

The result of any expression is its value.You can use the Script Editor to
display the result of an expression by typing an expression on a line by
itself and running the script. AppleScript returns the value of the expression. Here's an example:

1. Open the Script Editor if it is not already open.
2. Type the following expression in the editor subwindow:

   3 + 4

3. Click the Run button in the Script Editor window.

   This causes AppleScript to evaluate the expression.

4. Choose Show Result from the Controls menu.

   The result window displays the result of the evaluation, 7.