Using breakpoints
A breakpoint stops program execution so you can evaluate variables, fields, arrays, objects, and expressions; change the value of variables, arrays, and objects; and check what subroutine the program is in. Using breakpoints lets you run the program at full speed until it comes to a problem area; breakpoints give you an alternative to stepping through the entire program.
When you step or trace through a program, you’re essentially breaking at each line. However, once you are certain that no bugs exist in certain parts of your program, there is no need to repeatedly step through each line; instead, set breakpoints at crucial places where the code is less certain, then run the program at full speed and evaluate program values at the breakpoints.
If, for example, you suspect a bug in occurs at one particular place, such as when a subroutine is called, you could set a breakpoint at the line that calls the suspect subroutine. You could then step into the called method or function.
Setting and removing breakpoints
To set a breakpoint, select a line of code in the Source window and either
Move the pointer to the left of the command line where you want to enter a breakpoint. When the pointer changes to a Stop sign, double-click. The line is then highlighted in red.
To remove the breakpoint, double-click the highlighted line again.
Press Ctrl+B to add a breakpoint to the selected line of code or to remove a breakpoint from the selected line.
Choose Debug|Toggle Breakpoint from the Debugger menu (or from the Source window’s popup menu).
To remove all current breakpoints, choose Debug|Delete All Breakpoints.