File system Android. It needs to be mastered to optimize the work of the application and teach it to run each time, not from scratch, but to save its state between restarts. Also, the file system allows you to share data with other applications, such as uploading photos from the gallery.
The life cycle of the Android application. When the user works with your application, he or she can receive a call, an SMS, or another application will display a notification over the window. In such cases, you need to specify the program behavior, such as minimizing the window, pause, saving the current state or decreasing the volume of the sound. If you do not configure the application's life cycle, it will be inconvenient to use it.
Android technology solutions. Many applications perform the same actions, for example, request information from the Internet, search for information, or save data files. To avoid writing code for these actions from scratch, learn how to use libraries - typical solutions. These are parts of the code that work well and can be inserted into your application.
Navigation between screens. Most applications have multiple screens. For the user to be able to navigate between them, minimize or close them, you need to develop a navigation system and prescribe an action algorithm for each navigation method.
Working with sensors and touchscreens. Learn the SensorManager class to teach the application how to interact with sensors in your smartphone - accelerometer, gyroscope, distance and light sensors.
Application performance. Learn how to test and fine-tune performance so that your app doesn't consume a lot of resources or make your smartphone hang up.
Learn development tools
The main application development tool is Android Studio. The program consists of two parts:
Visual editor. Here you can specify the location of graphic elements of the future application manually, for example, drag and drop buttons.
Code editor. It says what to do when you press a button, zoom in or out, scrolling. You can write code in any language, such as Java or Kotlin.
Detailed video instructions for downloading and installing the code can be found here.
Where to start your career
Solve problems with Java. You can find them on the Javarush thematic site, inquests of Java Syntax, Java Collections, Java Core and others. Work on the tasks every day to master the language.
Switch to more complex projects - develop labyrinths, snakes, dictionaries and publish on GitHub. This way you can build your portfolio and show it to your employer.
Download applications from GitHub on Google Play. Even if you don't have thousands of downloads, you can include links to them in your resume.
Look at the vacancies and see which libraries are used by companies. Master Glide, Retrofit, Room, Fabric - many employers work with them.
Choose a potential employer and go to the interview as a Junior. If you are not hired immediately, they will recommend that you learn what to learn and what gaps in knowledge and skills to fill.
Frequent questions from newcomers
Do you need to know English to become an Android developer
Conversational English is not needed for development, but you will have to master the technical one. First of all, training materials can be read in Russian, technical terms in them will be consistent with English.
Whether it is possible to learn to develop mobile applications independently.
There are a lot of training materials available on the Internet in Russian and English, they can be mastered independently. But for understanding, it is necessary to learn the basics, and it is better to do it on courses under the direction of professionals. Teachers will help you to master the material from scratch, answer questions, give recommendations and conduct code review. It is better to work out the knowledge you have got at once in practice - after each lesson you need practical tasks.
Do you need to know math and get a specialized education.
To start programming, you don't need a university degree. Profile knowledge will be necessary if you work on the corresponding project.
Do you need to know everything about Android by heart?
No need, but it is important to be able to ask questions in the search engine and look for answers to them in the documentation, on specialized sites and forums. The developers have a large community, experienced programmers help beginners. Documentation is available in Android Studio, you can get useful information there.
What does Android have in common with HTML, CSS, Javascript
Mobile and web development are different industries. But if you know HTML, CSS, Javascript and understand programming principles, it will be easier to switch to Android.
You can use languages other than Java
Using Javascript, Python, C# and other alternative languages are only worthwhile if the decision is justified, and will save time and money. Most of the complex applications where you need to interact with your phone's hardware platform are better written in Java or Kotlin.
It is with Java that you begin your training courses, as the most common language is Java.