javascript closure interview question

local variables before exiting the function.2) The closure changes the value of the inner variable of the parent function outside the parent function. So, if you use the parent function as an object, and the closure as its public method, and the internal variable as its private property (private value), be careful not to arbitrarily change the value of the inner variable of the parent function.Liu, study q

codeThe Code is as follows:For (var I = 0; I SetTimeout (function (I ){Return function (){Console. log (I );}}) (I), 0 );} Three questions about JavaScript Closure 1. because the execution is asynchronous, when it is executed, it gets the value of variable I, then I = 10. so every time it is 10. after setTimeout, the execution will be delayed by 1 second. In 1 second, the for loop is certainly finished, so

7 JavaScript interview questions for true and false javascript questions The following seven JavaScript interview questions should be asked before the interview. Otherwise, your time may be wasted.1. What are the two methods for c

This article mainly shares 25 JavaScript interview questions that we need to know. If you want to pass the interview, refer 1. Use typeof bar === "object" to determine if bar is an object with potential drawbacks? How can we avoid such disadvantages? The disadvantage of using typeof is obvious (this disadvantage is the same as using instanceof ): let obj = {};l

This article mainly shares 25 JavaScript interview questions that we need to know. If you want to pass the interview, refer 1. use typeof bar === "object" to determine if bar is an object with potential drawbacks? How can we avoid such disadvantages? The disadvantage of using typeof is obvious (this disadvantage is the same as using instanceof ): let obj = {};l

. 14. briefly describe the implementation principles of unlimited classification in the forum. 15. design a webpage so that a full screen window is displayed when it is opened, which contains a text box and a button. After entering information in the text box, you can click the button to close the window, but the entered information is displayed on the main page. Interview Question 6 There is a table me

" "5" ABC ()//"6" "4" ABC ()//"7" "3" alert (x);//Error! "X" is undefined!See here, can you judge whether the code snippet of jquery is closed?As far as I understand it. If the closure feature is applied, you must determine if the code has the most important feature: a local variable that is not destroyed. It is clear, then, that the closure feature cannot be applied to anonymous functions without any imple

= "Plus">+1Button>4 ButtonID= "Minus">-1Button>5 Scriptsrc= "Test.js">Script> 6 Body>Second, in the JS code block put into the Window.onload event, the basic document structure to be loaded after the completion of the event binding:1Window.onload =function() {2 varplus = document.getElementById (' Plus ');3 varminus = document.getElementById (' minus '));4 varOutput = document.getElementById (' Output ');5Plus.addeventlistener (' click ',function() {6Console.log (' +1 ');7},

Inadvertently, see this Python interview question: What will the following code output? Def testfun (): temp = [Lambda x:i*x for I in range (4)] return tempfor Everylambda in Testfun (): Print (Everylam BDA (2)) in the mind silently a thought, this also uses to say, certainly is: 0246 last look answer, unexpectedly is: 6666 so with suspicion of mentality (actually is not admit defeat, do not admit the mista

methodGets the URL parameter function getquerystring (name) { var reg = new RegExp ("(^|)" + name + "= ([^]*) (|$)"); JS match returns an array of var r = location.search.substr (1). Match (reg); if (r! = null) { return r[2]; } else { return null;} }2) The other is the use of split combined with the array traversal implementation, this is relatively easy to implement the code is not affixed4, the regular expression removes the space5,

As a novice programmer interview or technical learning sometimes blind, no clue, in fact, look back, the general aspect is relatively clear.1. Java aspects(1) Java syntax(2) data structure, 8 kinds of basic data types, String, StringBuffer, Stringbuild,map, collection(3) Multithreading, lock, Singleton mode, thread pool(4) Message mechanism(5) agent, design mode(6) algorithm(7) database, MySQL, sub-Library sub-table, cluster, optimization-------------

Look at the online closure of the concept and article, for this problem, do a comb yourself. Q: What is a closure?A: Closures mean that in JavaScript, internal functions can always access the arguments and variables declared in the external function in which they reside, even after their external functions have been returned (the end of life). This is the first

Li tag of the page, and I am already 3. Example 2: ? 1 2 3 4 5 Ali[i].onclick = (function (i) {return function () {alert (i);}}) (i); The practice is to pass the function as the return value, passing the variable i through the parameters of the function, and then because the return function will refer to the I variable, the I variable will not be released when the For Loop ends. That is, the value of the I variable is saved in memory. Based on this principle, it is

One, closure of the package!?　　Closures (closure) are a difficult part of the JavaScript language and are not easy for beginners to understand, so let's take a look at the implications of closures.Baidu Encyclopedia and "official" explanation: the so-called "closure", refers to a lot of variables and the environment t

{Attribute 1: value 1; Property 2: Value 2; ...}9. What are the browsers that you have made? What are the cores of the browser?IE (ie kernel) firefox (Gecko) Google (WebKit) opear (Presto)10. How to solve several IE6 bugs1. Use display for double-sided bug float2.3 MP problem using float caused by use of dislpay:inline-3px3. Hyperlink hover After click fails to use the correct writing order link visited hover active4.Ie z-index problem add position:relative to Parent5.Png Transparent use JS cod

God's horse is a closed bag.On the concept of closures, the woman said that the woman is reasonable. A closure is a function that has access to a variable in another function's scopeThe concept is a bit round and split. Conceptually, closures have two features: 1. function 2, access to another function in the scope of variables Before Es 6, JavaScript had only the concept of functional scope

) { (function(j) {SetTimeout (functiontimer () {console.log (j); }, J* 1000); }) (i); //Create a separate scope for Each loop with an immediate execution function. } //Method 2 for(vari = 1; I ) {Let J= i;//Yes, the block scope of closures!SetTimeout (functiontimer () {console.log (j); }, J* 1000); } //Let Each loop create a block scopeToday's development is inseparable from modularity, the following is how the module uses closures.How the module uses closures:The mo

For the front-end newcomer, jquery was the interviewrelevant technical questions and answers are certainly essential, today and everyone to share isjquery Learning The common face questions and answers, hope that through the sharing of this article, can help new people better through the interview, a look at it. 1.jQueryin the library$()What is it? (The answer is as follows) $()function isjQuery ()a nickname for a function, at first glance it's weird,

= require ('. /test1 '); [javascript] view plaincopyname = 'foo' test1.test1 (); run: node test. the js result is: foo. There are some questions about global variables that need to be discussed in depth. We will continue to discuss them in the next article in view of the deviation from the topic here. Back to the previous question: 2. When we mention the context object this, we have to say the call and app

This article describes in detail a javascript interview question that is easily overlooked, if you are interested, you can refer to this question as the last question in a set of front-end interview questions. It is used to assess