You set breakpoints on an executable line of a program. When you debug the program, the execution is suspended before that line of code is executed.
To add a breakpoint:
In the editor area, open the file that you want to add the breakpoint to.
Notice that the left edge of the C/C++ editor has a blank space called a marker bar.
With your pointer, hover over the marker bar beside the exact line of code where you want to add a breakpoint. Right-click the marker bar and select Toggle Breakpoint.
A dot appears, indicating the breakpoint:
A corresponding dot also appears in the Breakpoints view, along with the name of the file in which you set the breakpoint.
To add a breakpoint at the entry of a function, in either the Outline view, or the left margin of editor view in the C/C++ perspective, right-click a function and select Toggle Breakpoint.