beginning
Recently, many netizens have reported that the information they obtained from various places is too messy, fragmented, and fragmented. When I look at it, I think it is quite useful, but after a long time, I can't remember anything. In fact, this is the consequence of the lack of systematic learning .
In order to improve your learning efficiency, help you to quickly master the various knowledge points of Android development. I have compiled a system of advanced study notes for Android developers .
This set of materials not only contains **[Android Developer System Core Knowledge Notes] and [2021 latest interview with real questions]**, a total of 2983 pages of PDF, 580,000 words. Can't show all
PS : This is a high-quality Android communication circle. There are many first-line technical experts in the group, as well as code farmers who are struggling in small factories or outsourcing companies. The members of the group are very active. Here, not only can you gain the workplace experience and guidance of your predecessors, but the old apes are also willing to answer your technical questions.
One, java interview questions
Proficiency in Java is very important. Large companies not only require you to use several APIs, but also require you to be familiar with the principles of source code implementation, and even to know what are the shortcomings, how to improve, and some algorithms related to Java. , Design patterns and so on.
(1) Java basic interview knowledge points
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The difference between == and equals and hashCode in java
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How many bytes does int, char, and long occupy?
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The difference between int and integer
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Tan Tan's understanding of java polymorphism
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String、StringBuffer、StringBuilder区别
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What is an inner class? The role of inner classes
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The difference between abstract class and interface
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The meaning of abstract classes
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Application scenarios of abstract classes and interfaces
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Can an abstract class have no methods and attributes?
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The meaning of the interface
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The difference between extends and super in generics
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Can the static method of the parent class be overridden by the child class
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The difference between process and thread
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The difference between final, finally, finalize
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Serialization method
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The difference between Serializable and Parcelable
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Can static properties and static methods be inherited? Can it be rewritten? And why?
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Design intent of static inner classes
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Understanding of member inner classes, static inner classes, local inner classes and anonymous inner classes, and the application in the project
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Talk about the understanding of kotlin
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The difference between closure and local inner class
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The method and principle of converting string to integer
(two) java in-depth source-level interview questions (difficult) -
Under what circumstances will objects be disposed of by the garbage collection mechanism?
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Tell me about common encoding methods?
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How many bytes does the Chinese in utf-8 encoding occupy; how many bytes does int type?
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What is the difference between static proxy and dynamic proxy, and in what scenarios?
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Java's exception system
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Talk about your understanding of parsing and dispatch.
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Modify the signature of the equals method of object A, then when using HashMap to store this object instance, which equals method will be called?
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What is the mechanism to achieve polymorphism in Java?
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How to serialize a Java object into a file?
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Talk about your understanding of Java reflection
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Talk about your understanding of Java annotations
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Talk about your understanding of dependency injection
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Talk about the principle of generics and give an example
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Understanding of String in Java
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Why should String be designed to be immutable?
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The equal and hashCode methods of the Object class are overridden. Why?
(3) Data structure -
Introduction to common data structures
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What do you know about concurrent collections?
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List java collections and the inheritance relationship between collections
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Collection class and collection framework
Introduction to container classes and the difference between them (container classes estimate that many people have not heard the word, Java containers can be divided into 4 parts: List list, Set collection, Map mapping, tool class (Iterator iterator, Enumeration enumeration class, Arrays and Collections), you can see this blog post Java container class http://alexyyek.github.io/2015/04/06/Collection/ for details)
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The difference between List, Set, Map
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Implementation and storage of List and Map
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The realization principle of HashMap
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HashMap data structure?
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HashMap source code understanding
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How to put data in HashMap (explained from the perspective of HashMap source code)?
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How to implement HashMap by hand?
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The realization principle of ConcurrentHashMap
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Comparison of ArrayMap and HashMap
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HashTable implementation principle
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Concrete implementation of TreeMap
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The difference between HashMap and HashTable
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The difference between HashMap and HashSet
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How do HashSet and HashMap determine that the set elements are duplicated?
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How to prevent collisions when implementing Hash in Set
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The difference between ArrayList and LinkedList, and application scenarios
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The difference between array and linked list
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Specific implementation of depth-first traversal and breadth-first traversal of binary trees
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Heap structure
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The difference between heap and tree
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What is the difference between heap and stack in memory (answer hint: you can answer from two aspects: data structure and actual implementation)?
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What is deep copy and shallow copy
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Handwritten linked list reverse code
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Talk about the understanding of the tree, B+ tree
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Talk about the understanding of the graph
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Determine whether the singly linked list is a ring or not?
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Linked list flip (ie: flip a single necklace table)
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Combine multiple singly ordered linked lists (assuming that they are all increasing)
Learning welfare
[Android detailed knowledge point mind map (skill tree)]
In fact, there are so many knowledge points in Android development, and there are still a few things to ask in interviews. Therefore, there are no other tricks for the interview, just look at how well you prepare for these knowledge points. So, when you go out for an interview, it is good to see which stage you have reached in your review.
Although Android is not as hot as in previous years, the era of finding high-paying jobs with the four major components has passed. This can only show that the positions below the intermediate level of Android are saturated. Now senior engineers are still relatively lacking . Many senior positions give very high salaries (you may not be able to find a suitable one if you have more money), so I strive to become a senior engineer. is the most important.
Attached here are dozens of sets of ByteDance related to the above-mentioned interview questions, interview questions from JD.com, Xiaomi, Tencent, Toutiao, Ali, Meituan and other companies in 19 years. The technical points are organized into videos and PDFs (in fact, it took a lot of effort than expected), including knowledge + many details.
Due to limited space, I will show you a small part in the form of pictures.
The detailed arrangement is visible by clicking on GitHub;
Android architecture video + BAT interview topic PDF + study notes
There are a lot of materials for learning Android on the Internet, but if the knowledge learned is not structured, and when you encounter problems, you just taste it and don’t study it in depth, then it is difficult to achieve real technological improvement. I hope this systematic technical system can provide you with a direction reference.
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There are a lot of materials for learning Android on the Internet, but if the knowledge learned is not structured, and when you encounter problems, you just taste it and don’t study it in depth, then it is difficult to achieve real technological improvement. I hope this systematic technical system can provide you with a direction reference.