Android learning resources: list of the best tutorials, free courses, documentations

KOTLIN
1. We suggest completing a training course to get acquainted with the basic idioms and
  syntax of the language. The course is available in two versions: either in the browser
  or through a plugin for Android Studio or IntelliJ IDEA.
2. If you have any questions on some topic from the previous step, we advise you to read
  this topic in the documentation.
ANDROID
1. The website provides all the required documentation on the Android platform, from basic components to analysis of specific libraries involved in development.
2. Dive into Clean Architecture
3. A suite of libraries from Google to ensure backward compatibility between Android versions and provide more functionality for Android applications
4. Glide, Picasso, and Fresco are libraries that simplify displaying images from various sources.
5. Coroutines are a current trend in working with multithreading. Official
  documentation and documentation in the Android context.
1. A library that implements the Observable pattern and knows about the program lifecycle.
2. This is one of the implementations of the Dependency Injection pattern. It
  allows making our code more modular and independent.
3. A library that allows testing Android applications without running an emulator.
USEFUL ARTICLES
1. Multithreading:
2. Collections:
  - Overview of the collections: Collections Framework Overview and Collections in Java
  - A series of articles about ArrayList – Java Collections: Under the hood — ArrayList E01 and Internal Working of ArrayList in Java
  - A series of articles about Linked List – Java Collections: Under the hood — LinkedList E01
  - HashMap: HashMap in Java with Examples and Java HashMap internal Implementation 5
  - LinkedHashMap: Java LinkedHashMap Internal Implementation and Java LinkedHashMap And Its’ Difference From HashMap
  - The main library that all Java and Kotlin testing is built around.
3. For those who are interested in deepening their knowledge of Java, data structures and
  algorithms, and learning how to write beautiful and efficient code:
  - Basic Java course
  - Robert Martin – Clean Code
  - Cay S. Horstmann; Gary Cornell. – Java 2. Library of the Professional, Volume 1. Fundamentals. 8th edition. This book covers the variety of elements necessary for successful development.
  - E. Gamma, R. Helm, R. Johnson, J. Vlissides. – Design Patterns: Elements of Reusable Object-Oriented Software.
  - Eric Freeman, Elizabeth Freeman, Kathy Sierra, Bert Bates – Design Patterns.
  - Robert Lafore – Data Structures and Algorithms in Java.
  - Bruce Eckel. Thinking in Java

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Learning resources Android

Learning resources
Android