Shulou(Shulou.com)06/03 Report--

Today, I will talk to you about the interview questions about Android, which may not be well understood by many people. in order to make you understand better, the editor has summarized the following contents for you. I hope you can get something according to this article.

Android Foundation

View drawing process; custom View how to consider model adaptation; custom View event distribution mechanism; what event distribution related callback methods are available for View and ViewGroup respectively; how custom View provides an interface to obtain View attributes

Art and Dalvik comparison; virtual machine principle, how to design a virtual machine (memory management, class loading, parent delegation); JVM memory model and class loading mechanism; circular reference and avoidance of memory objects

Memory recovery mechanism and GC algorithm (advantages and disadvantages of various algorithms and application scenarios); GC principle timing and GC objects; memory leak scenarios and solutions; OOM avoidance and solutions

Four major components and life cycle; privilege management of ContentProvider (read-write separation, permission control-accurate to table level, URL control); comparison of four startup modes of Activity; Activity state is saved in recovery

Fragment lifecycle; Fragment state preservation

Which class is the method of startActivityForResult, under what circumstances is it used, and how should it be decoupled if used in Adapter?

AsyncTask principle and its deficiency; IntentService principle

What's the difference between AstncTask+HttpClient and AsyncHttpClient?

How to ensure that a background service will not be killed; what is the way to save power?

How to intercept and abort a short message through broadcast; whether the broadcast can request the network; the time limit of anr caused by broadcast

Interprocess communication, AIDL

Handler Mechanism and its underlying implementation

Binder Mechanism and its underlying implementation

The difference between ApplicationContext and ActivityContext

The calculation of the memory occupied and memory occupied by a piece of Bitmap

How do you do this for applying updates? (grayscale, forced update, regional update)

Mixed development, RN,weex,H5, Mini Program (it is good to know some front-end js, etc.)

Name an application that you think is popular and design it (live APP)

Java Foundation

Collection class and collection framework; HashMap and HashTable implementation principles, thread safety, hash conflicts and processing algorithms; ConcurrentHashMap

The difference between processes and threads; multithreading and thread pools

How to ensure data consistency; Synchronized keywords, class locks, method locks, reentrant locks

Methods of synchronization; multi-process development and multi-process application scenarios

The server only provides data receiving interface, under the condition of multi-thread or multi-process, add editor Wechat: AMEPRE, how to ensure the orderly arrival of data

ThreadLocal principle, implementation and how to guarantee Local attributes

String StringBuilder StringBuffer comparison

Interface and callback; the principle of callback; write a callback demo

The principle of generics, with examples; analysis and dispatch

The difference between abstract classes and interfaces; application scenarios; whether abstract classes can be without methods and properties

Can static properties and static methods be inherited? Can it be rewritten? Reason

Modify the signature of the equals method of object A, so which equals method will be called when HashMap is used to store the object instance

Data structure and algorithm

What is the difference between heap and stack in memory (data structure and actual implementation)

Which is the fastest sorting algorithm? Which algorithm should be chosen to rank Ali's more than 20,000 employees by age? The difference between a heap and a tree; write fast code; list reverse code

Find the number of daffodils within 1000 and the number of daffodils within 4 billion

Code implementation of substring inclusion problem (KMP algorithm)

How to find the difference C of two URL files An and B at trillion level (Bit mapping-> hash grouping-> multi-file read and write efficiency-> disk addressing and application level optimization of addressing)

Ant Colony algorithm and Monte Carlo algorithm

Write out the sorting algorithm you know and the spatial complexity and stability.

How to try to find the nearest merchant function in Baidu POI (coordinate mirror + R tree)

Other

Four necessary conditions for deadlock

Common encoding methods; Chinese in utf-8 coding occupies a few bytes; int type several bytes

Implement a Json parser (speed can be improved by regularization)

A common design pattern in MVC MVP MVVM;; write code for the observer pattern

TCP's three handshakes and four waves; the difference between TCP and UDP

HTTP protocol; the difference between HTTP1.0 and 2.0; HTTP message structure

The difference between HTTP and HTTPS and how to achieve security

Summary of non-technical questions

What are the more in-depth areas of study?

What are the channels to pay attention to the information in the industry?

What books have you read recently?

The technical points that you are best at, the technical areas and technical points that you are most interested in

Which open source libraries are used in the project and how to avoid the security and stability problems caused by the introduction of open source libraries?

What did you do and what did you produce during the internship?

Five coins, how to divide 2 heads and 3 sides into two stacks, and then flip the two stacks so that the number of coins facing up is the same as the number of coins facing up.

Walk around the hour hand and coincide with the minute hand several times

N * N checkered paper, how many squares are there?

Now that the download speed is very slow, try to analyze the reasons from the point of view of the network protocol and optimize it (all 5 layers of the network can be involved)

Summary of HR question

Tell me the one thing that impresses you most.

Introduce a project that has the greatest influence on you.

Introduce the areas of expertise that you love best.

What is the biggest achievement of company internship?

What are your strengths and weaknesses? Give examples to illustrate

What is your learning method? How to learn during the internship? What is the biggest difficulty encountered in the internship project and how to solve it?

Say one thing that can best prove your ability.

What is the biggest difficulty encountered in the project? How to solve the problem?

Your career planning and personal goals; your future development path and job search positioning

Evaluate yourself, evaluate your technical level and the amount of personal code.

Through which channels to learn about the recruitment information, which companies have other students invested in?

What are your hobbies in your spare time

Current offer status; how to choose if all BATH are given to offer

What aspects do you value more about a job? Platform, technology, atmosphere, city, money

Ideal salary range; which do you choose, Hangzhou or Beijing?

What is the ideal working environment?

What do colleagues / classmates have to learn from during the internship?

Your family's expectations of your job and your own job expectations.

If the boss misunderstands you at the public meeting, how to solve it?

Can you do an internship? how long can you practice?

What do you see in the company? Or what aspects of the company attract you the most?

After reading the above, do you have any further understanding of the interview questions of Android? If you want to know more knowledge or related content, please follow the industry information channel, thank you for your support.

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