This material came from pages on qbasic.phatcode.net, unfortunately they no longer appear to be available.
- You can debug as you program – no need to restart the application after making a code change in most cases.
- Watch Expression – Monitor the value of a variable as one moves through the code.
- Watchpoint – Stops the program when a monitored value/expression becomes true (nonzero).
- Watch Window – Appears at the top of the screen during program execution.
- True = -1; False = 0
- You have to add a watch for each part of the program in which one wants to monitor a variable/expression.
- You must select trace on command from the debug menu before debugging the program.
- Add Watch – Displays values of variables and expressions as they change during the program’s execution, displayed at the top of the screen.
- Instant Watch – Move the cursor within or to the right of a variable or select an expression and choose instant watch from the debug menu.
- Shift + F9.
Tracing and History
- Tracing – Turns on history and allows you to see the last twenty statements executed as well as the twenty statements about to be executed.
- Trace On – Steps through the app in slow motion, highlighting each statement as it is executed.
- Trace on Command – Highlights each statement as it executes.
- Normal Tracing – Run entire program at once.
- Single Stepping – One statement at a time.
- Procedure Stepping – One procedure at a time.
- Breakpoint – A place in a program where execution should pause.
- History Back – Interrupt program execution using CTRL+BREAK.
- Use Shift + F8 to check the last twenty statements.
- History Forward – Can only be used after using History Back.
- Use Shift + F10.
- Toggle Breakpoint
- Break on Errors
- Set Next Statement
- Immediate Window – Appears at the bottom of the screen.
- Use it to input code directly and execute it.
- Accesses code in the currently active module/procedure.