What are the most effective ways to identify the root cause of a bug?

1 Use a debugger tool

A debugger tool is a software that allows you to inspect and manipulate the state of your code while it is running. You can use a debugger tool to set breakpoints, watch variables, evaluate expressions, and step through your code line by line. A debugger tool can help you isolate the exact location and cause of a bug by showing you the values and behaviors of your code in real time. There are various debugger tools available for different mobile platforms and languages, such as Android Studio, Xcode, Visual Studio, and Flutter.

2 Write unit tests

Unit tests are small pieces of code that test the functionality and logic of a specific component or module of your code. Unit tests can help you identify the root cause of a bug by verifying the expected output and behavior of your code under different scenarios and inputs. Unit tests can also help you prevent introducing new bugs or breaking existing features when you make changes to your code. You can use a testing framework, such as JUnit, XCTest, NUnit, or Dart, to write and run unit tests for your mobile application.

3 Use logging and crash reporting

Logging and crash reporting are techniques that allow you to record and analyze the events and errors that occur in your code during runtime. Logging is the process of printing or saving messages that describe the state and actions of your code, such as variables, parameters, functions, and exceptions. Crash reporting is the process of collecting and sending information about the crashes that happen in your application, such as stack traces, device details, and user feedback. Logging and crash reporting can help you identify the root cause of a bug by providing you with valuable clues and insights into what went wrong and why. You can use a logging library, such as Logcat, NSLog, NLog, or Print, to implement logging in your code. You can also use a crash reporting service, such as Firebase Crashlytics, App Center, Sentry, or Bugsnag, to monitor and manage crashes in your application.