You can interact with a running program using the Interactive Ruby Console which may be docked or put into its own tabbed page. In addition to providing a simple way to give input and view output to and from a program, the Ruby Console can also be used to evaluate expressions when you have stopped at a breakpoint while debugging.
Expression Evaluation
When stopped at a breakpoint, you may evaluate mathematical expressions or call Ruby methods in the Ruby Console. To evaluate a variable, simply enter its name.
Hover and Drill-Down
When you have stopped at a breakpoint, you can enter the name of a variable into the editable part of the Ruby Console. Hover the mouse over the variable name to view drill-down details of that variable.
See Also
Debugging
The Debugger