react js interview questions

Vim Training) SSH security enhancement method, password mode and RSA key mode configuration. Rpm/apt/yum/ports Pack, query, delete the basic commands. (Answer reference this article: Ubuntu Command Daquan series five--software installation) Makefile's basic format, GCC compilation, connection commands,-o0 and-o3 differences. (The answer refers to this article: configure, make, and make install in Linux compilation installation respectively) Basic use of gdb,strace,valgrind.

?What are the Nginx load balancing? If one of the servers hangs up, how does the alarm mechanism be implemented?26. If not optimized, what is the maximum number of Apache connections? Nginx General Maximum number of connections is? MySQL insert per second? Select? Update? Delete?What are the MySQL data types? How much storage space do you use separately?Nginx set Cache js, CSS, pictures and other information, the implementation of the principle of cac

Php interview question 1. use PHP to print the time format of the previous day in the format of 22:21:21 (2 points) "u % j q! S $} 0 V8 ~ 4? #? Date ("Y-m-d H: I: s", strtotime ("-1 days ")); 2. differences between echo (), print (), and print_r () (3 points)Echo is a PHP statement, print and print_r are functions, and the statement does not return values. the function can return values (even if it is not used)Print () can only print values of s

This article is mainly to share with you common PHP interview questions summary, mainly in the form of text and we share, hope to help everyone. 1. Look at your CV and ask about the user volume, PV, throughput, difficulties and solutions of past projects. 2. Database design experience, why do the sub-table? The Sub-Library?How much data do you usually start a table? The Sub-Library? What is the purpose of

This article is translated from: Https://www.toptal.com/php/interview-questions, the article listed in the question although seemingly simple, but each behind the one or a few people are easy to ignore the basic points of knowledge, Hope to help you with your interview and your usual work. Q1 The first question about weak types $str 1 = ' Yabadabadoo '; $st

1. Tell me about your understanding of doctype.2.web Product Development process3. Tell me about your understanding of the box model4. What are the three layers of the front page? What is the role?5. What are the inline elements? What are block-level elements? How do they transform each other?What are the introduction methods of 7.CSS?8. Please use CSS to define 9. Talk about CSS Sprites technology10. In which browsers did you test the page? What are the cores of these browsers? What are the com

Before I resigned, I gave my company a set of interview questions. What do you think is difficult ?? Oracle Database assessment: 1. Write a jdbc connection to the database and add, delete, modify, and query data code (simply write it ). Answer: PublicstaticvoidMain (String [] args ){ //TODOAuto-generated method stub Connection cn =Null; CallableStatement cstmt =Null; Try{ // Do not do this here, because th

configuration. While JavaScript is interpreted to perform without generating intermediate files, "read a sentence, execute a sentence", the execution can generally be done in three ways:1. The general browser comes with the JS interpreter, which can be used directly by the browser;2. Special interpreter software can be installed node. js, executing the. js file;

= "Aaaabbbccccddfgh"; var obj = {};for (var i=0;i10, write a function, clear the string before and after the space. (compatible with all browsers)function Trim (str) {if (str typeof str = = = = = = "string") {return str.replace (/(^\s*) | ( \s*) $/g, ""); Remove front and back blank characters}}other1. What is the process of a complete HTTP transaction? Basic Flow:A. Domain Name resolutionB. 3-time handshake to initiate TCPC. Initiating an HTTP request after establishing a TCP connectionD. ser

!) ）What is 11,sass and less? Why do you use them?They are CSS pre-processors. He is a layer of abstraction on CSS. They are a special kind of grammar/language compiled into CSS.For example, less is a dynamic style language. CSS is assigned to dynamic language features such as variables, inheritance, operations, and functions. Less can be run on the client (ie 6+, Webkit, Firefox) or on the server (with node. js).Why use them?The structure is clear an

JavaScript Interview Requirements: the following questions must be selected from one to four, three questions, implemented using native code, cannot be usedIn any framework, the fifth question is selected.1. display images in a fixed area of the page1. Each time you click the right arrow, the image area will scroll to the left and vice versa;2. When an image is f

reasonable allocation of server resources Cpu:apache MySQL in high-load environment, disk IO read and write too much, will certainly occupy a lot of resources, it is inevitable that the CPU occupies too high. Memory: Memory library, database software hard disk: file web2.0 architecture Select MongoDB+redis or mysql+Memcached is a better combination, the logic is simple to use NoSQL current main web site architecture LAMP, LNMP, LLMP now there is a lnamp architecture on the network, which is the

Highlights of PHP interview questions compiled by NLP. PHP Basics 1. find the value of $ a and copy the code as follows: $ ahello; $ bunset ($ B); $ bworld; echo $ a; 2. find the value of $ B and copy the code as follows: $ a1; $ x $ B $ a + PHP Basics 1. evaluate the value of $ The code is as follows: $ A = "hello ";$ B = $;Unset ($ B );$ B = "world ";Echo $; 2. evaluate the value of $ B The code i

For the PHP interview questions compiled by NLP, from basic to advanced, if you want to apply for a php job, refer. The basic PHP knowledge section is also referenced by recruitment institutions. 1. evaluate the value of $ The code is as follows: $ A = "hello "; $ B = $; Unset ($ B ); $ B = "world "; Echo $; 2. evaluate the value of $ B The code is as follows: $ A = 1; $ X = $; $ B = $ a ++; Echo $

nested, must have root element, all XHTML elements must be nested within the root element5, to the Web standardization (or site reconstruction) know what the relevant knowledge, briefly describe a few of the Web standards you know?　　Web standardization is divided into structural standardization, performance standardization, behavior standardization. The structure standard language has XHTML and XML, the performance standard language CSS, the behavior standard language w3c,ecmscriptWeb standardi

the reuse of the cell without confusion. After the data is configured, by updating the constraint, the frame of the last control can be determined only by determining the height that the cell actually needs, and caching it, the next time it is acquired, the judgment exists, and if it exists, it returns directly. Therefore, it is calculated only once.20. How does the UITableView calculate the content height? Why does the proxy method that gets the row height call the data bar several times when

grouping, the ultimate subtraction, Use selection instead of input, label and text arrangement, Rely on the plaintext to confirm the password, reasonable keyboard utilization, In the interview, is actually an interactive link, not only to answer questions, but also seize the opportunity to get the initiative, want to ask some questions abo

A common webfront-end interview question (JS) and webjs Interview Questions are a topic of great interest to recruitment companies and developers. The company hopes to learn the real level and detailed processing capabilities of developers through this topic, developers want to maximize their own level (or even play ex

functions are promoted to the top of the current function. For example, the following code: console.log('x' in window);//truevar x; x = 0; When the code is executed, the js engine promotes the declaration statement to the top of the code and changes it: var x;console.log('x' in window);//truex = 0; Function expression Both var getName and function getName are declaration statements. The difference is that var getName is a function expression,

I gather a lot of questions about the JS Foundation, and share with you the success of the interviewWhat are the Q1,javascript data types?Don't underestimate the problem oh, this question is very humble but difficult to answerThe answer I recommend is from the essence of javacript language.The simple types of JavaScript include numbers, strings, Boolean values (True and false), null values, and undefined va