Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

Use Toggle Breakpoint (or press F9) to turn breakpoints
on and off. Breakpoints are markers placed on statements
in your program. If you run your program and it encounters
a breakpoint, the program stops on that statement. QBasic
highlights the breakpoint line.
 
To turn a breakpoint on and off:
  1. Move the cursor to the line you want the breakpoint
     on, or to a highlighted breakpoint line.
  2. Choose Toggle Breakpoint (or press F9).
 
Use a breakpoint to pause your program at a point where
you suspect problems, then:
  ■ Print the values of variables in the Immediate window.
  ■ Single step your program from the breakpoint forward.