Debugging is the process of identifying and resolving errors or bugs in a software application, which helps improve the app’s quality, performance, and functionality.
To debug an iOS app on an iPhone, you need the following:
An iPhone connected to your Mac via a USB cable or a wireless network.
Xcode installed on your Mac, which is an integrated development environment (IDE) for creating, testing, and debugging iOS apps.
A registered developer account with Apple, which can be a free or paid account obtained from the Apple Developer website.
A provisioning profile and a signing certificate associated with your developer account and your app. The provisioning profile contains information about your app and authorized devices, while the signing certificate verifies your identity as the app developer.
Launch Xcode on your Mac and open your app project.
Connect your iPhone to your Mac using a USB cable or a wireless network. You might need to unlock your iPhone and trust your Mac if prompted.
In Xcode, select your iPhone as the target device from the scheme pop-up menu in the toolbar. Alternatively, you can go to Window > Devices and Simulators and choose your iPhone from the list of devices.
Click on the Product menu in Xcode and select Clean Build Folder. This action clears any cached or outdated files from your project and prepares it for debugging.
Next, click on the Product menu again and choose Run. This will build and run your app on your iPhone. You may be prompted to enter your developer account credentials.
To attach the debugger to your app process on the iPhone, click on the Debug menu in Xcode and select Attach to Process by PID or Name. Alternatively, you can use the keyboard shortcut Command + Shift + A.
In the dialog box that appears, enter the name of your app’s process and click on Attach. If you know the process ID (PID) of your app, you can enter it here. You can find the PID of your app using the ps -ax command in the Terminal app on your Mac.
You can now use various debugging tools and features in Xcode to debug your app, such as:
Breakpoints: These are markers that pause the app’s execution at specific lines of code or conditions. You can add, remove, enable, disable, or edit breakpoints using the breakpoint navigator, the gutter, or the breakpoint editor in Xcode. Keyboard shortcuts like Command + \ can add or remove a breakpoint, and Command + Y can enable or disable all breakpoints.
Console: This pane displays the app’s output, including print statements, logs, errors, and warnings. You can use the console to enter commands or expressions that interact with your app or debugger. Keyboard shortcuts like Command + Shift + C can show or hide the console, and Command + Shift + Y can show or hide the debug area containing the console and other debugging tools.
Variables: These are containers that store values or data in your app. The variables view in Xcode allows you to inspect or modify variable values. Keyboard shortcuts like Command + Shift + I can show or hide the variables view, and Command + Option + I can show or hide the inspectors pane with various options for viewing variables.
Debugging Commands: These commands control the app’s execution or the debugger, including stepping over, stepping into, stepping out, and continuing. You can use debugging commands via the debug bar, the console, or keyboard shortcuts in Xcode. For example, F6 steps over a line of code, F7 steps into a function or method call, F8 steps out of a function or method call, and Command + R continues running your app.
Debugging an iOS app on an iPhone is crucial for identifying and fixing errors or bugs in your app. To do so, make sure you have the necessary hardware and software set up, connect your iPhone to your Mac, select it as the target device in Xcode, run your app on the iPhone, and attach the debugger to the app process in Xcode. Use Xcode’s various debugging tools and features, such as breakpoints, console, variables, and debugging commands, to efficiently debug and enhance your app’s quality, performance, and functionality.