Evaluate Expression... allows you to inspect the current state of your program. When your scripts stops at a breakpoint, you can use the action Run → Evaluate Expression… to inspect it.
It works like the
echo command. It evaluates and prints the expressions you enter into this dialog. That’s why you need to prefix variables with the dollar sign
$ and why you need to quote string values.
Here are some examples of expression evaluation:
At this time, the expression evaluation only allows to print values. It doesn’t support modifications.