QA Official

java and C++ C comparison

https://qaofficial.com/post/2019/05/20/72098-java-and-c-c-comparison.html 2019-05-20
I first learned C, then contacted C++, then became interested in android, and then learned java. Let's start with C, which is usually at the bottom, writing code such as driver logic.The so-called embedded system is generally C. To learn C well, it is necessary to have data structure. Many beginners think that C and data structure are the same thing.In fact, the data structure is more of an idea and algorithm.

numpy: finds the index of the specified element

https://qaofficial.com/post/2019/05/20/72207-numpy-finds-the-index-of-the-specified-element.html 2019-05-20
Purpose: Know the index of the specified element in numpy arrayFunction: np.argwhere >>>x >>>array([[0, 1, 2], [3, 4, 5]]) >>>np.argwhere(x>1) >>>array([[0, 2], [1, 0], [1, 1], [1, 2]])

python lambda Expression: Understanding and Using key Parameters of max Function in python

https://qaofficial.com/post/2019/05/20/72205-python-lambda-expression-understanding-and-using-key-parameters-of-max-function-in-python.html 2019-05-20
The new version is very 6. The preview effect is different from the actual display. I am speechless when the code block is displayed in html format.Let's see. I saw this usage when looking at other people's code before: return max(self._children.items(), key=lambda act_node: act_node[1].get_value(c_puct)) indicates that he is very confused about this key value, and then searches the internet.Oh!Reference material lambda expression: lambda is actually a Anonymous function. We usually

A Summary of the Differences between C Language and C++, C++ and JAVA

https://qaofficial.com/post/2019/05/20/72078-a-summary-of-the-differences-between-c-language-and-c-c-and-java.html 2019-05-20
C and C C language is process-oriented and focuses on algorithms and data structures..The first consideration in the design of C program is how to get the output (or implement process (transaction) control system) through an operation process on the input (or environmental conditions). As software becomes more and more complex, code becomes longer and longer, and one's brain power is limited, one often writes to the back and forgets

Cas single sign-on system can be applied in mobile terminal, PC terminal, javaweb and separation of front and back terminals

https://qaofficial.com/post/2019/05/20/72218-cas-single-sign-on-system-can-be-applied-in-mobile-terminal-pc-terminal-javaweb-and-separation-of-front-and-back-terminals.html 2019-05-20
said in front: the original cas single sign-on system was specially developed for javaweb, so in supporting javaweb, it is awkward to say so, or directly replace it with Jsp, that is to say, we basically do not need to make too many changes in jsp, we need to modify the authentication method, and we need to verify the few changes such as bills.But for other directions, we should make some efforts, especially when the front and back ends of html are separated.

Common language explains what RPC framework is

https://qaofficial.com/post/2019/05/20/72122-common-language-explains-what-rpc-framework-is.html 2019-05-20
RPC framework responsibilities RPC framework should shield various complexities from callers and from service providers: 1. 调用方感觉就像调用本地函数一样 2. 服务提供方感觉就像实现一个本地函数一样来实现服务Local Procedure Call RPC is to tune remote functions just

Comparison of HTTP and RPC Communication Protocols

https://qaofficial.com/post/2019/05/20/72139-comparison-of-http-and-rpc-communication-protocols.html 2019-05-20
seven-layer model of OSI network structure The detailed description of each layer is as follows: The 7th Floor: The application layer defines the interface-user program for communication and data transmission in the network;Providing standard services, such as transmission and processing of virtual terminals, files and tasks;The sixth layer: the presentation layer covers up the differences of data formats between different systems;Specifies the data transmission format of the independent structure;Encoding and decoding of data;Encryption and decryption;Compression and decompressionThe fifth layer: the session layer manages user sessions and dialogues;Controls the establishment and hanging up of logical connections between users;Reports errors that occurred at the previous levelThe fourth layer: the transport layer manages the end-to-end information transmission in the network;Providing reliable and orderly data packet transmission through error correction and flow control mechanisms;Providing the transmission of data packets from ConnectionlessCommunication;Layer 3: The network layer defines how data is transmitted between network devices.

Deep and Shallow RPC-Shallow and Shallow+Deep

https://qaofficial.com/post/2019/05/20/72121-deep-and-shallow-rpc-shallow-and-shallow-deep.html 2019-05-20
In recent years, service and Microservices have gradually become the mainstream of medium and large distributed system architecture, and RPC plays a key role in it.In normal daily development, we all use RPC implicitly or explicitly. Some programmers who have just entered the industry will find RPC mysterious. While some programmers who have many years of experience in RPC use have rich experience, some are also not very know clearly about its principle.

From C++ to Java (1)

https://qaofficial.com/post/2019/05/20/72081-from-c-to-java-1.html 2019-05-20
The first step is actually to download the software and construct the compilation environment, but it is very troublesome!!I won't talk about it, hehe. 1, the characteristics of Java 1. Simple.2. Object-oriented. 3. Platform independent (OS and processor (Central Processor)): When compiling C language and C++, different executable files will be formed for different platforms, so those compiled for platform A cannot be used for B.

From java to c

https://qaofficial.com/post/2019/05/20/72080-from-java-to-c.html 2019-05-20
1) Stack Area: Automatically Allocated and Released by CompilerGenerally store the parameter values of functions, the values of local variables, etc.2) heap area: allocated and released by programmers.If the programmer does not release it, the OS may recycle it after the program ends.3) Register area: used to store the stack pointer and instruction pointer4) Global area (static area): Global variables and static variables are stored together.Initialized and uninitialized are separate.After