Breaking on a line number

When you break on a particular line of code, execution stops whenever that line of code is executed.

To set a breakpoint on a particular line:

When a breakpoint is set on a line number, the breakpoint is shown in the Source window by an asterisk in the left column. If the Breakpoints window is open, the method and line number is displayed in the list of breakpoints.

You can toggle the breakpoint on and off by repeatedly double-clicking or pressing F9.