How can you use breakpoints to debug iOS apps with Xcode?

2 Running and stopping breakpoints

To run your app with breakpoints, you need to select a simulator or a device from the scheme menu and click on the run button or press Command + R. Your app will launch and run normally until it reaches a breakpoint. Then, your app will pause and you will see the debug area at the bottom of the Xcode window. The debug area consists of three parts: the console, the variables view, and the debug navigator. You can use these parts to examine your app's state and interact with it. To resume the execution of your app, you can click on the continue button or press Command + Option + P. To stop your app, you can click on the stop button or press Command + . (period).

3 Using breakpoints navigator

The breakpoints navigator is a useful tool to manage and organize your breakpoints. You can access it by clicking on the breakpoints button in the navigator area or pressing Command + 8. The breakpoints navigator shows you a list of all the breakpoints in your project, grouped by file and function. You can enable or disable breakpoints, edit their properties, delete them, or move them to another location. You can also create breakpoint groups and folders to categorize your breakpoints and share them with other developers.

4 Adding breakpoint actions

Breakpoint actions are commands that you can assign to your breakpoints to perform certain tasks when your app pauses. For example, you can use breakpoint actions to log a message, play a sound, capture a screenshot, or execute a shell script. To add a breakpoint action, you need to right-click on a breakpoint in the source code editor or the breakpoints navigator and select Edit Breakpoint. Then, you can click on the Add Action button and choose an action from the menu. You can also set a condition for your breakpoint action to run only when a certain expression is true.

5 Using conditional breakpoints

Conditional breakpoints are breakpoints that only pause your app when a certain condition is met. For example, you can use conditional breakpoints to pause your app only when a variable has a specific value or when a loop reaches a certain iteration. To set a conditional breakpoint, you need to right-click on a breakpoint in the source code editor or the breakpoints navigator and select Edit Breakpoint. Then, you can enter an expression in the Condition field and click on Done. You will see a small C icon next to your breakpoint indicating that it is conditional.

6 Using exception breakpoints

Exception breakpoints are breakpoints that pause your app when an exception is thrown. Exceptions are errors that occur when your app encounters an unexpected or invalid situation, such as a nil object, an out-of-bounds array, or a division by zero. Exception breakpoints can help you identify and fix the source of these errors. To set an exception breakpoint, you need to click on the + button at the bottom of the breakpoints navigator and select Exception Breakpoint. Then, you can choose the type of exception you want to catch (Objective-C, Swift, or both) and the breakpoint behavior (break on throw or break on catch). You will see a purple icon next to your exception breakpoint indicating that it is active.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?