javascript advanced interview questions and answers

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

Questions about function call variables var a =10; function aaa(){ alert(a); } function bbb(){ var20; //10 } bbb(); Variable declaration issues function aaa(){ var a=b=10; } aaa(); alert(a);//not defined alert(b);//10 Variable lookup is the nearest principle to find, Var defined variables, when the nearest is not found, will look for the outer layer: var10 funct

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

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

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

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

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 =

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

Article category: Web Front-endI. multiple choice questions 1. Which of the following statements will generate a running error :()A. var obj = ();B. var obj = [];C. var obj = {};D. var obj = //; 2. Which of the following words does not belong to a reserved javascript word :()A.B. parentC. classD. void 3. Select a true expression :()A. null instanceof ObjectB. null === undefinedC. null = undefinedD. NaN = Na

I. multiple choice questions 1. Which of the following statements will generate a running error? () A. var OBJ = (); B. var OBJ = []; C. var OBJ = {}; D. var OBJ = //; Comments: OBJ = [] defines an array object, OBJ = {} defines an object literal, OBJ = // defines JavaScript does not write var OBJ = () as a regular object! 2. Select the true expression for the result: (c) A. null instanceofObject