During debugging, the variables pane in the result drawer plays an expanded role. Each time the script pauses, the names and values of all variables currently in scope are displayed. Thus, the variables pane is an important tool for understanding what your script is doing. In the variables pane:

• Variables inherited from the higher AppleScript world come first, and have a blue background.

• Variables local to the current scope come next, and have a yellow background.

• Variables globally visible to the current scope come last, and have a white background.

• A variable whose value has changed since the last pause is displayed in red.

What variables are shown depends not only upon the current scope but also on the current stack frame. Click on a line of the call stack, and the variables listed will change to reflect the selected stack frame.

There is usually a result each time script pauses, namely the result of the most recently executed line of code. This is shown in the result pane, not the variables pane.

Important note: To have local variables appear during debugging, you should explicitly declare them (with a local statement) in your script. This is especially the case with local variables in handlers.

Another way to see variable values is through tooltips that appear when you hover the mouse over an expression in your script. A Debugger preference sets the conditions under which these appear.

The variables pane is an explorer view, with all the abilities that this entails. For example, individual lines of the variables pane can be separated into individual viewer windows. If you leave open a viewer window on a variable that you’re interested in, it will be updated automatically each time the script pauses.

Furthermore, variables without a “read-only” icon () are editable in the variables pane! Select a line and press the Return key (or choose Edit Value from the contextual menu). Using this feature, you can experiment with the behavior of your script as it runs.