common javascript interview questions

Difference between Forward and Redirect in common JAVA interview questions, forwardredirect The user sends an HTTP request to the server, which may be returned to the user after being processed by multiple information resources. Each information resource uses the request forwarding mechanism to forward requests to each other, however, the user does not feel reque

Original reference Https://mp.weixin.qq.com/s/mCVL6qI33XeTg4YGIKt-JQ1. Event BrokerAdds an event to the parent element, using the event bubbling principle, to get child elements based on E.targetLet Parentbox = document.getElementById (' Parentbox ');Parentbox.addeventlistener (' click ', Function (e) {if (e.target e.target.nodename = = = ' LI ') {Let item = E.target;Console.log (item);}})2. Using closures in loopsvar arr = [1,2,3,4,5];for (var i=0; iSetTimeout (function () {Console.log (i)},10

--; Swap (Num[i], num[j]);2. Since j is the first element greater than I, after the Exchange, II starts to the end, still satisfies the descending order, the direct reverse gets the increment arrangement. Note that the flip starts from II.After the exchange, it is still in descending order. Reverse (Num.begin () + II, Num.end ());3. Simple memory steps Looking forward from the end of the end to two adjacent elements, both satisfying I If no such pair of elements are

1. Jesus has 13 disciples, one of whom is a traitor to betray Jesus, please use the rule of exclusion to find the traitor: 13 people sitting around, starting from the first person to cycle off, count to three exclude, the last remaining person is a traitorint people[13] = {1,2,3,4,5,6,7,8,9,10,11,12,13};int count = 0;//is used to record a datagramint number = 13;//Records aliveint i = 0;//record number of people are on the count.while (number > 1) {if (people[i]! = 0) {count++; If a[i] is not re

1. String S1 = ' 123 ';String s2 = new string ();2. The difference between two ways of implementing multithreadingInheriting the thread and implementing the Runnable interface3. Single-column design mode What's the difference between lazy and a hungry man? * * *Lazy style Features: lazy loading. Delayed loading in multi-threaded security problems, through the addition of synchronization to solve, plus synchronization efficiency is low, with a double-judge method to solve the low efficiency. The

as 2:32 below, indicates how long the system has been running since the last start.[[email protected] DOWNLOAD] #uptime02:05:22 up 2:32, 2 users, Load average:0.00, 0.00, 0.0014. How to add route in Linux systemHost routingRoute add-host 192.168.197.100 Dev eth0Gateway RoutingRoute add default GW 192.168.197.1Network routingRoute ad-net 192.168.1.0 netmask 255.255.255.0 deveth1Route ad-net 192.168.1.0 netmask 255.255.255.0 gw192.168.197.115. The contents of the known Test.txt file are as follow

. Synchronize the data between the main library and the library, and then repeat the action again13. Use a single command to turn off all services except SSHD, Crond, network, Rsyslog services (no power-on automatic)Method One:[[Email protected]~]# for name in ' Chkconfig–list|grep 3:on|awk ' {print '} ' |grep-ev "sshd|crond|rsyslog|network" ';d och Kconfig $name Off;done[Email protected]~]# chkconfig–list|grep 3:onCrond 0:off 1:off 2:on 3:on 4:on 5:on 6:offNetwork 0:off 1:off 2:on 3:on 4:on 5:o

line ------------ I will add that the essence of closure is static scope. Because JavaScript does not have a dynamic scope, function accesses are all defined scopes, so closures can be implemented. In other words, closures are built-in runtime functions. But in fact, isn't any function in JavaScript a function that comes with a runtime environment? Some people think that all functions are closures. This is

are not placed under the sub-domain name, but placed in a separate primary domain name. There is also a reason that the browser for a domain name will have a limit on the number of requests, this method can be convenient to do CDN.What are the states of the readystate of 23.ajax, and what are the meanings respectively?Ajax readystate A total of 5 states, respectively, 0-4, each of which means that the meaning of each number is 0 is not called the Open method, 1 means that the Send method is not

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

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;3. Executed with the Web page, using the Third, the data typeJava is a strongly typed lang

developer's knowledge about JavaScript inheritance and prototype attributes.Question 3: HoistingWhat is the output result of the following code?Function test (){Console. log ();Console. log (foo ());Var a = 1;Function foo (){Return2; } }Test (); answerUndefined and 2.The above code is equivalent to the following code:Function test (){Var;Function foo (){Return2; }Console. log ();Console. log (foo ());A = 1; }Test (); Question 4: how to executeThe

. Conversely, when Getfullname () is assigned to the test variable, the context refers to the Global Object (window). This is because test is a property that is implicitly set to the global object. For this reason, the function returns the FullName of the window, that is, the value defined in the first row.Question 5:call () and apply ()Now let you solve the previous problem and make the final Console.log () print Aurelio De Rosa.　　ReplyThe problem can change the function context by forcing the

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

Topic:var array = [1, [2, 3, [4, 5,], 6], 7, 8];Write a method Flatarray (array), get [1, 2, 3, 4, 5, 6, 7, 8]Answer:1. Two force notation:function Flatarray (arr) { var temp = arr.join (). Split (', '), = temp.length, = []; for (var i=0; i) { Result.push (parseint (Temp[i])); } return result;}　2. Recursion:functionFlatarray (arr) {varresult = []; for(vari = 0, L = arr.length; I ){ if(Arr[i]instanceofArray) {Result=Result.concat (Arguments.callee (arr

Which of the following javascript interview questions have you done?1. -------------------------------------------------- copy the code var fun = function () {this. name = 'Peter '; return {name: 'jack'};} var p = new fun (); copy the code to ask p. name is: a: 'Peter ', B: 'jack', c: null, d: undefined 2. -------------------------------------------------- copy t

1.----------------------------------------------------var function () {this. Name = ' Peter '; return ' Jack '}; var New Fun ();Excuse me, p.name is:A: ' Peter ', B: ' Jack ', C:null, d:undefined2.----------------------------------------------------var function () {this. Name = ' Peter '; return ' Jack '; var New Fun ();Excuse me, p.name is:A: ' Peter ', B: ' Jack ', C:null, d:undefined3.----------------------------------------------------var function =' peter '}}varnew fun (); var New =

[Interview Questions] Android interview questions, questions android questions Android interview questions The

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 exceptionally well ). This article provides a wide range of front-end development interview

on different sending objects. (Function call is used to send messages) B. The implementation principle is dynamic binding, and the method called by the program is dynamically bound at runtime. tracing the source code can find that JVM can find a suitable method through automatic parameter transformation.For more resources, visit the Java backend interview summary. Various Java-based resources Interpretation of Java engineers from the