This view displays information about the variables in the currently-selected stack frame.
When a thread suspends, the top stack frame of the thread is automatically selected. When stack frame is selected, you can see the visible variables in that stack frame in the Variables view.
The Variables view shows the value of primitive types. Complex variables can be examined by expanding them to show their members.
When the VM suspends a thread (due to hitting a breakpoint or stepping through code), you can evaluate expressions in the context of that thread's stack frame.
Select the stack frame in which an evaluation is to be performed. For the detail panes of the Variables and Expressions views, the evaluation context will be a selected variable. If no variable is selected, the selected stack frame will be the context.
Expressions can be entered and evaluated in the following areas:
Detail pane of the Expressions view
Detail pane of the Variables view
Java editor when it is displaying source and it is not read-only
Select the expression to be evaluated and select Display or Inspect from the context pop-up menu. The result of evaluating the expression is shown in the Display view (if Display was chosen), or in the Expressions view (if Inspect was chosen).
NOTE: Evaluations cannot be performed in threads that have been manually suspended.