Using Flex Builder 2 > Programming Flex Applications > Running and Debugging Applications > Debugging your applications > Adding and removing breakpoints

Adding and removing breakpoints

You use breakpoints to suspend the execution of your application so that you can inspect your code and use the Flex Builder debugging tools to explore options for fixing errors. You add breakpoints in the code editor and then manage them in the Breakpoints view when you're debugging your applications.

You add breakpoints to executable lines of code. The debugger stops only at breakpoints set on lines that contain the following:

• MXML tags that contain an ActionScript event handler, such as
  <mx:Button click="dofunction()" ...>
• ActionScript lines such as those enclosed in an <mx:Script> tag or in an ActionScript file
• Any executable line of code in an ActionScript file

You can set breakpoints as you're coding or while you're debugging.

To set a breakpoint in the code editor:

1. Open a project file that contains ActionScript 3.0 code.
2. Locate the line of code on which you want to set a breakpoint and in the marker bar double-click to add a breakpoint.

   The marker bar is along the left edge of the code editor.

   A breakpoint marker is added to the marker bar and to the list of breakpoints in the Breakpoints view of the Flex Debugging perspective.

   When the debugger encounters a breakpoint, the application is suspended, the debugging perspective is displayed, and the line of code marked with a breakpoint is highlighted in the code editor. You then use the debugging commands to interact with the code. (See Managing the debugging session in the Debug view).

To remove a breakpoint in the code editor:

• In the marker bar, double-click an existing breakpoint.

  The breakpoint is removed from the marker bar and the Breakpoints view of the Flex Debugging perspective.

You manage breakpoints in the Breakpoints view. You can remove one or all breakpoints in the list or disable them and re-enable them at a later time (see Managing breakpoints in the Breakpoints view).

Related topics

• Starting a debugging session
• Setting Run/Debug preferences
• Managing breakpoints in the Breakpoints view
• Managing the debugging session in the Debug view
• Managing variables in the Variables view
• Using the Expressions view

Flex 2.01