Tag closedness, labels, unscrupulous nested, increasing the chance of searching robot search, using external chain CSS and JS scripts, structural performance separation, file download and pages faster, content can be accessed by more users, content can be accessed and content Codes and components that can be accessed by more widespread devices are easy to maintain and modify. They do not need to change the content of the page, provide printing versions without copying content, and improve the use of websites;
What is the difference betweenxhtml and html
HTML is a basic web web design language. XHTML is the main difference between XML -based labeling language:
The XHTML element must be nested correctly.
XHTML elements must be closed.
The label must be a lowercase letter.
XHTML documents must have root elements.
3.DOCTYPE? Strict mode and mixed mode-how to trigger these two modes, what is the significance of distinguishing them?
Used to declare the document using that specification (HTML/XHTML) generally, the HTML document with strict excessive framework based on the framework is triggered by the XML statement, and the analysis method is changed to IE5.5 bug with IE5.5.
4. What are the elements in the line? What are the block -level elements? CSS box models?
Block -level element: DIV P H1 H2 H3 H4 FORM UL
Element in the line: AB BR I span input select
CSS box model: content, border, margin, padding
5. What are the ways to introduce bycss? The difference between Link and @import is?
Internal and internal internal internal internal in -link guidance
Difference: Load at the same time
The former is not compatible, the latter does not support the browser below CSS2.1
LINK supports the use of JavaScript to change the style, which cannot be
6. What are the chosen selection symbols? What attributes can inherit? Priority algorithm
How to calculate?
Which of the internal and Important is high?
Tag Selection Syllabus Selection ID Id Selection Character
Inheritance is not as good as specified ID> class> label selection
The latter is high priority
7. What are the three layers of the front -end page and what are the differences? What is the role?
Structure layer HTML represents layer CSS behavior layer JS
8. The basic sentence composition ofCSS?
Selector {Properties 1: Value 1; Properties 2: Value 2; ...}
9. What are the pages you made?
What is the core?
IE (IE kernel) Gecko (webkit) Open (Presto)
10. Write several solutions to IE6 BUG
1. Use Display caused by bilateral distance bug float
2.3 Pixel problem uses DISLPAY: Inline -3px caused by Float
3. Howl link hover after clicking the correct writing order Link Visited Hover Active
4.Ie Z-IDEX problem adds Position: Relative
5. PNG transparent use JS code change
6. min-height minimum height! Important solution '
7.Select to cover with iframe nesting under IE6
8. Why is there no way to define the width container about 1px (IE6 default line
Caused by Over: Hidden, Zoom: 0.08 line-height: 1px)
11. What is the difference between the Title and Alt property on the label?
ALT is represented by text when the picture does not display.
Title provides information for this attribute
12. Describe the role and use of CSS Reset.
Reset reset the CSS default attribute browser varieties of the browser,
Different styles, then reset it, let them unify
13. Explain how to use CSS Sprites.
The CSS elf integrates a bunch of small pictures into a large picture,
Reduce the number of requests on the server
14. What is the difference between the standard mode and weird mode of the browser?
Different in box model rendering mode
Use window.top.document.comPatmode
Can display why mode
15. How do you optimize the documents and resources of the website? The anticipated solution includes:
File merger
File minimize/file compression
CDN hosting
Cache use
16. What is a semantic HTML?
Awareness of the tag is good for the search engine's grabbing
17. Several ways to remove floats, their respective advantages and disadvantages
1. Use the empty label to clear the floating Clear: Both (theoretically clear can be clear
Any label ,,, add meaningless labels)
2. Use Overflow: Auto (empty tag element to remove float without
Do not increase the disadvantages of unintentional code, use Zoom: 1 for compatible IE)
3. Clear float with Afert pseudo elements (for non -IE browser)
Javascript1. What data types of JavaScript's Typeof return
Object Number Function Boolean Underfind
2. Example 3 compulsory type conversion and 2 hidden type conversion?
Compulsory (PARSEINT, PARSEFLOAT, NUMBER)
Hidden (== - ===)
3. The difference between wlit () join ()
The former is the form of cutting into a group, and the latter is to convert the array into a string
4. Array method POP () push () unshift () shift ()
Add Pop () tail delete at the tail of push ()
Unshift () head adds shift () head delete
5. What are the differences between event binding and ordinary events
6. Different from the flow and DOM event stream
1. The execution order is different,
2. The parameters are different
3. Do not add on the event
4. ahis pointing to the problem
7. What are compatible writing methods under the II and Standards
Var EV = EV || Window.event
document.documentelement.clientWidth || Document.body.clientWidth
Var target = EV.Srcelement || EV.Target
8. The difference between get and post methods when requesting
One is placed in the virtual carrier behind the URL
There are size restrictions
Security Question
Different applications are forums and so on.
9. The difference between call and apply
Object.call (this, obj1, obj2, obj3)
Object.apply (this, arguments)
When 10.Ajax request, how to explain JSON data
Eval Parse is more reliable to use PARSE in view of security considerations
11.B how to inherit A
12. Write a function to get a non -line style
Function GetStyle (Obj, Attr, Value) {if (! value) {if (obj.currenStyle) {Return Obj.currenStyle (attr)} Else {obj.getComputestyle (Attr, FALSE) }} else {obj.style [ATTR ] = Value}}13. What is the commission of the incident
Let the principle of bubbling in the event, let the events triggered, let his parent element be performed!
14. What is the closure, what are the characteristics, and the impact on the page
Closing is a function that can read other internal variables of other functions.
1. Save the variable I to each paragraph object (P)
1. Function Init1 () {
2. var Pry = document.GetelementsBytagname (P);
3. For (var I = 0; I <prry.length; i ++) {
4. Pary [i] .i = i;
5. Pary [i] .onClight = Function () {
6. Alert (this.i);
7.}
8.}
9.}
2. Save the variable i in the anonymous function itself
1. Function Init2 () {
2. var Pry = document.GetelementsBytagname (P);
3. For (var I = 0; I <prry.length; i ++) {
4. (Pary [i] .onClight = Function () {
5. Alert (ARGUMENTS.CALLEE.I);
6.}). I = i;
7.}
8.}
3. Add a closure of a layer of closure, i transmits it to the inner layer function in the form of a function parameter
1. Function init3 () {
2. var Pry = document.GetelementsBytagname (P);
3. For (var I = 0; I <prry.length; i ++) {
4. (Function (ARG) {
5. Pary [i] .onClight = Function () {
6. Alert (ARG);
7.};
8.}) (i); // Parameters when call
9.}
10.}
4. Add a closure of a layer of closure, i transmits it to the inner layer function in the form of a local variable
1. Function init4 () {
2. var Pry = document.GetelementsBytagname (P);
3. For (var I = 0; I <prry.length; i ++) {
4. (Function () {
5. VAR TEMP = i; // Local variables when calling
6. Pary [i] .onClight = Function () {
7. Alert (TEMP);
8.}
9.}) ();
10.}
11.}
5. Add a closure of a layer and return a function as a response event (pay attention to the subtle difference from 3)
1. Function init5 () {
2. var Pry = document.GetelementsBytagname (P);
3. For (var I = 0; I <prry.length; i ++) {
4. Pary [i] .onClight = Function (ARG) {
5. Return function () {// Return a function
6. Alert (ARG);
7.}
8.} (i);
9.}
10.}
6. For implementation with function, in fact, every function instance will generate a closure
1. Function init6 () {
2. var Pry = document.GetelementsBytagname (P);
3. For (var I = 0; I <prry.length; i ++) {
4. Pary [i] .onClight = New Function (Alert ( + I +);); // NEW generates a function instance at a time
5.}
6.}
7. Implement with function, pay attention to the difference from 6
1. Function init7 () {
2. var Pry = document.GetelementsBytagname (P);
3. For (var I = 0; I <prry.length; i ++) {
4. Pary [i] .onClight = Function ('Alert ('+I+')');
5.}
6.}
15. How to stop incident bubbling and default events
Cancebubble Return false
16. Add to delete and replace the method of inserting into a certain contact
obj.appendchidl ()
obj.innersetBeFore
obj.replacechild
obj.removechild
17. Explain the principle of jsonp, and why it is not the real Ajax
Dynamically create a Script label, callback function
Ajax is a pageless refresh request data operation
18. The local object of JavaScript, built -in object and host object
The local object is Array Obj Regexp, etc.
The built -in object is GLOAD MATH, etc.
Documen, Window, etc. that the host comes with the browser
19. The difference between Document Load and Document Ready
Document.onload is the execution of JS after loading the structure and style
Document.ready native species does not have this method, jQuery has available
$ (). Ready (function)
20. == and === Different
The former will automatically convert the type
The latter will not
21. JavaScript's homologous strategy
A script can only read the attributes of windows and documents from the same sources,
The same source here refers to the combination of host name, agreement and port number
22. Write a way to go heavy for array
Function OSORT (ARR)
{{
var result = {};
var newarr = [];
for (var I = 0; I <arr.Length; i ++)
{{
if (! Result [arr])
{{
newarr.push (ARR)
result [arr] = 1
}
}
Return Newarr
}
23. Media selector
@Media (min-width: 992px) and (max-width: 1199px)
@Media Screen and (min-width: 768px)
HTML & CSS
1. What are the commonly used browser tests? What kernels (Layout Engine)?
(Q1) Browser: IE, Chrome, Firefox, Safari, Opera.
(Q2) kernel: Trident, Gecko, Presto, Webkit.
2. Speaking of the differences between the downlink elements and block level elements? What are the compatibility of the inner block element? (IE8 below)
(Q1) In -line elements: It will be arranged in the horizontal direction, which cannot include block -level elements, and the Width is invalid.
Height is invalid (you can set line-height), Margin is invalid, padding is invalid.
Block -level elements: each occupies a line, and the vertical direction is arranged. From the end of the new line, one was disconnected.
(Q2) Compatibility: Display: Inline-Block;*Display: Inline;*Zoom: 1; 1;
3. What are the ways to remove floats? Which is better?
(Q1)
(1) Definition of Height DIV.
(2) Empty DIV tag at the end.
(3) Family DIV definition pseudo: After and Zoom.
(4) Definition of Overflow: Hidden.
(5) Definition of Overflow: Auto: AUTO.
(6) The parent DIV also floats and needs to define width.
(7) Definition Display: Table.
(8) Add BR tag Clear: Both at the end.
(Q2) It is better for the third method. Many websites are used like this.
4. What are the attributes commonly used inbox-sizing? What is the role?
(Q1) Box-sizing: Content-box | border-box | Inherit;
(Q2) Content-box: The width and height are applied to the content box of the element, respectively.
Draw the interior and border of the element outside the width and height (the default effect of the element).
border-box: Any interior and frame specified in the element will be set up
Draw width and height. A decrease from the set width and height respectively
Only the width and height of the content can be obtained by the border and the interior distance.
5.Doctype? What are the differences between the standard mode and compatibility mode?
(Q1)>! DoCTYPE <Inform what documents to use the browser's parser
Standard analysis of this document. DOCTYPE does not exist or incorrect formats will cause text
The file is presented in a compatible mode.
(Q2) The typesetting and JS operating mode of the standard mode are the most supported by the browser
High standard operation. In compatible mode, the page is loose and backward
Show that the behavior of simulation old browsers is used to prevent the site from being unable to work.
6.html5 Why only need to write>! DoCTYPE HTML <?
HTML5 is not based on SGML, so there is no need to reference DTD, but
Need doctype to regulate the behavior of the browser (let the browser follow them
It should be run).
HTML4.01 is based on SGML, so it needs to be referenced to DTD
Inform the type of documentation used in the browser document.
7. When the page is imported, what is the difference between using Link and @import?
(1) LINK belongs to the XHTML label. In addition to loading CSS, it can also be used
To define RSS, define the role of REL connection attributes, etc.; and @import is CSS mention
For the supply, it can only be used to load CSS;
(2) When the page is loaded, LINK will be loaded at the same time, and @import quotes
The CSS will wait until the page is loaded before loading;
(3) Import is proposed by CSS2.1. It can only be recognized only above IE5.
Link is the XHTML label, which is not compatible;
8. Introduce your understanding of the browser kernel?
Mainly divided into two parts: rendering engine (Layout Engineer or
Rendering Engine) and JS engines.
Rendering engine: Responsible for obtaining the content of the webpage (HTML, XML, Image, etc.),
Sort the message (such as adding CSS, etc.), and the display method of calculating the webpage,
Then output to the display or printer. Different core of the browser's kernel
The grammatical interpretation of the webpage will be different, so the effect of rendering is different.
All web browsers, email clients, and other needs to be edited,
Applications that display network content require the kernel.
JS engine: Analyze and execute JavaScript to achieve the dynamic effect of the webpage.
At first the rendering engine and the JS engine did not distinguish it clearly. Later
With more and more independent, the kernel tends to refer to rendering engines.
9. What are the new features ofhtml5? How to handle the browser and both the new label of HTML5
Could it be questioned? How to distinguish HTML and HTML5?
(Q1)
HTML5 is no longer the subset of SGML, mainly about the increase in functions such as images, positions, storage, and multi -tasks.
(1) Painting canvas;
(2) Video and Audio elements used for medium;
(3) Local offline storage LocalStorage storage data for a long time, the data is not lost after the browser is closed;
(4) The data of sessionStorage is automatically deleted after the browser is closed;
(5) Better content elements, such as Article, FOOTER, Header, Nav, Section;
(6) Form control, Calendar, Date, Time, Email, URL, Search;
(7) New technology WebWorker, WebSocket, Geology; Geology;
(Q2)
IE8/IE7/IE6 supports labels generated by document.createElement.
You can use this feature to allow these browsers to support the new label of HTML5.
After the browser supports the new label, the default style of the label also needs to be added.
Of course, you can also use mature frameworks, such as HTML5SHIM;
>--[if lt IE 9] <] <
> Script <src = http://html5shim.googleCode.com/svn/trunk/html5.js>/script <
>! [Endif]-<
10. Briefly describe your understanding of HTML semanticization?
Do the right thing with the right label.
HTML semantic has a structured content and clearer structure, which is convenient for browsers and search engines;
Even if there is no style CSS, it is displayed in a document format, and it is easy to read;
The crawler of the search engine also depends on the HTML mark to determine the weight of the context and the keywords of each keyword, which is conducive to SEO;
It makes people who read the source code easier to separate the website for the website, so that it is easy to read maintenance and understanding.
Javascript
1. Introduce the basic data type of js
Undefined, NULL, Boolean, Number, String
2. What are the built -in objects of JS?
Data packaging objects: Object, Array, Boolean, Number, String
Other objects: Function, Arguments, Math, Date, Regexp, ERROR
3. understanding of athis object
This always refers to the direct caller of the function (rather than indirect caller);
If there is New keywords, this object points to the NEW;
In the incident, this points to the object of the incident. In particular, in IE
This in Attachevent always points to the global object Window;
4. What does Eval do?
Its function is to resolve the corresponding character string into JS code and run;
Eval should be avoided, unsafe, and very consuming (2 times, resolved into JS statements at a time, one execution).
When converted from the JSON string to the JSON object, you can use EVAL, VAR OBJ = EVAL (' + Str +') ');
5. How to add, remove, move, copy, create and find nodes
// Create a new node
createdocumentfraagment () // Create a DOM fragment
createElement () // Create a specific element
createTextNode () // Create a text node
// Add, remove, replace, insert
APPENDCHILD ()
Removechild ()
replacechild ()
insertBeFore () // Insert a new sub -node before the existing child node
// Find
Getelementsbytagname () // Through the label name
GetelementsByname () // The value of the name property of the element
(IE fault tolerance capacity is strong, and a array will be obtained, including the ID is equal to the name value)
Getelementbyid () // Through element ID, uniqueness
6. The difference between Null and Undefinine?
NULL is an object that does nothing, which is 0 when turning to value; undefined is a
The original value that indicates nothing is nan when it turns to value.
undefined:
(1) Variables are declared, but when there is no assignment, it is equal to UNDEFINED.
(2) When calling the function, the parameters that should be provided are not provided. This parameter is equal to undefined.
(3) There is no attribute of the object, and the value of this attribute is UNDEFINED.
(4) When the function does not return the value, the UNDEFINED is returned by default.
null:
(1) As a parameter of the function, the parameter of the function is not an object.
(2) The end of the primary chain of the object.
7. What do theNew operating symbol do?
(1) Create an empty object, and the this variable references the object,
At the same time, the prototype of the function was also inherited.
(2) The attributes and methods are added to the object referenced by this.
(3) The newly created object is cited by this, and the final hidden type returns this.
8. JSON understanding?
JSON (JavaScript Object Notation) is a kind of light
Overweight data exchange format. It is a subset of JavaScript.
The data format is simple, easy to read and write, and occupies small bandwidth.
Format: Use key values pairs, for example: {'Age': '12', 'name': 'back'}
9. The differences and functions of call () and Apply ()?
The Apply () function has two parameters: the first parameter is the context, the second
The parameter is an array composed of the parameter. If the context is NULL, use the global object instead.
Such as: function.apply (this, [1,2,3]);
The first parameter of the call () is the context, and the subsequent parameter sequence passed by instances.
Such as: function.call (this, 1,2,3);
10. How to get UA?
function whatBrowser () {
document.browser.name.value = navigator.appname;
document.browser.version.Value = navigator.appversion;
document.browser.code.value = navigator.appcodename;
document.Browser.agent.Value = navigator.useragent;
}
other
1. What dohttp status code knows?
100 Continue continues, usually when sending post requests, it has been sent
After the http header, the server will return this information to indicate confirmation, and then send specific parameter information
200 ok normal return information
The 201 Created request was successful and the server created new resources
202 Accepted server has accepted the request, but has not been processed
The webpage requested by 301 Moved Permanently has permanently moved to a new position.
302 Found temporary redirection.
303 SEE Other temporarily redirect, and always use Get to request new URI.
304 Not Modify has not been modified since the last request.
The 400 Bad Request server cannot understand the format of the request, and the client should not try to use the same content to initiate a request again.
401 unauthorized requests are not authorized.
403 Forbidden is forbidden to access.
404 Not Found cannot find a resource that matches the URI.
500 Internet Server Error's most common server -side error.
503 Service Unavailable server is temporarily unable to process requests (probably overloaded or maintenance).
2. What kind of performance optimization methods do you have?
(1) Reduce the number of HTTP requests: CSS Sprites, JS, CSS source code compression, large picture
Small control is appropriate; webpage GZIP, CDN hosting, Data cache, picture server.
(2) The front -end template JS+data is reduced to bandwidth waste due to the HTML label.
The front -end variable saves the Ajax request results.
(3) Use InnerHtml to replace the DOM operation, reduce the number of DOM operations, and optimize the performance of JavaScript.
(4) ClassName is set when many styles you need to set up instead of directly operating style.
(5) Use the results of global variables and cache DOM nodes. Reduce IO reading operation.
(6) Avoid using the CSS Expressionion (CSS expression), also known as Dynamic Properties.
(7) Pre -load of the picture, put the style table on the top, put the script to the bottom and add a timestamp.
3. What is elegant downgrade and gradual enhancement?
Elegant relegation: Web sites can work normally in all new browsers. If users make
The old -fashioned browser is used, and the code will check to confirm whether they can work normally.
Due to the problem of IE's unique box model layout, for different versions of the HACK practice of IE
The elegance has been downgraded, adding the candidate plan for those browsers that cannot support the function,
Make it a relegation experience in the old browser in some form, but it will not be completely invalidated.
Graduation enhancement: Starting from the basic functions supported by all browsers, gradually add those
The function of only new browsers is supported, adding a harmless amount of the basic browser to the page
External style and function. When the browser supports, they will automatically present and play a role.
4. Which common operations can cause memory leakage?
Memory leakage means that any object still exists after you no longer own or need it.
The garbage recovery device scan the object regularly and calculates the number of other objects of each object.
If the number of references of an object is 0 (no other object has quoted the object),
Or the only reference to the object is circular, then the memory of the object can be recycled.
The first parameter of the settimeout uses a string instead of a function, which will cause memory leakage.
Closure, console log, cycle (when two objects quote each other and retain each other, a cycle will be generated)
5. The difference between thread and process
There is at least one process in a program, and a process has at least one thread.
The division scale of the thread is less than the process, making the complication of multi -threaded programs high.
In addition, the process has an independent memory unit during execution, and multiple threads share memory,
As a result, the operation efficiency of the program is greatly improved.
The thread is still different from the process during execution. Each independent thread has one program
Exit of sequences and sequences and sequences of sequencing. But threads cannot be independent
Execution must be performed according to the application of multiple threads in the existence of the application.
From a logical perspective, the significance of multi -threading is that in one application, there are multiple executions
Part can be executed at the same time. But the operating system does not regard multiple threads as multiple independent ones
Applications to achieve process scheduling and management and resource allocation. This is the process and thread
Important differences.
Front -end development engineer face test question JavaScript
1. Methods that can be used dynamically to change the content in the layer are (AB)
a) InnerHtml
b) Innertext
c) Realize by the hiding and display of the setting layer
d) Display attributes of the style attribute of the layer layer
2. When pressing the keyboard A, the result of printing Event.keycode with the onkeydown event is (A)
a) 65
b) 13
c) 97
d) 37
3. In JavaScript, the following options are not an array method (b);
a) sort ()
b) length ()
c) Concat ()
d) Reverse ()
4. Which of the following options can be used to retrieve the index number of the selected option? (B)
a) Disabled
b) SelectedIndex
c) Option
d) Multiple
5. I hope the picture has the same function of the submission button. How to write a form submission? (A)
a) Manually submit in the onClick event of the picture
b) Add an onSubmit event to the picture
c) Manually submit in the ONSUBMIT event of the picture
d) Submit automatically in the form
6. The code that makes the DIV layer and the text box is correct (d);
A)
B)
C)
D)
7. In the following options, the correct description is (select two items). (AD)
a) Options.add (New Option ('A', 'A')) can dynamically add a drop -down list option
b) Option.add (New Option ('A', 'A')) can dynamically add a drop -down list option
c) New Option ('A', 'A') 'a' represents the value of the list option, 'a' is used to display on the page
d) New Option ('A', 'A') 'a' represents the value of the list option, 'a' is used to display on the page
8. VAR EMP = New Array (3);
for (var I in EMP)
In the following answers, it can be replaced with the for loop code: (select one). (D)
A for (var I = 0; i
B for (var I = 0; i
C for (var I = 0; i
D for (var I = 0; i
9. When the function of making a class dishes is called the (A) incident of the drop -down list box.
a) Onchange
b) Onfocus
c) Selected
d) Onclick
10. In the following statements of the array, the wrong option is (C).
a) var arry = new array ()
b) var arry = new array (3)
c) var arry [] = new array (3) (4)
d) var arry = new array ('3', '4')
11. Which of the following attributes can achieve layer hiding? (C)
a) Display: FALS
b) Display: Hidden
c) Display: None
d) Display:
12. Which of the following options is not a method of Document object? (D)
a) Focus ()
b) GetelementByid ()
c) GetelementsByname ()
d) bgcolor ()
13. Which of the following is pressing the keyboard event (AB)
a) onkeydown
b) onkeypress
c) keycode
d) Onmouseover
14. The purpose of JavaScript to verify form verification is (B)
a) Submit the correct information of the user to the server
b) Check the data submitted data must meet the reality
c) Make the page beautiful and generous
d) Reduce the pressure on the server side
15. The commonly used value of the Display attribute value does not include (C)
a) Inline
b) Block
c) Hidden
d) None
16. The following statements about the Pixeltop attribute and TOP attribute are correct. (D)
a) All attributes of Location objects
b) The return values when use are all string
c) All return the value of pixels
d) The above is not right
17. Use the Open method to open the window with browser tools, address columns, menu bars. The following options are correctly __D__
a) Open (x.html, hi, toolbas = 1, scrollbars = 1, status = 1);
b) Open (hi, scrollbars = 1, local = 1, status = 1);
c) Open (x.html, status = yes, menubar = 1, local = 1);
d) Open (x.html, hi, toolbas = yes, menubar = 1, local = 1);
18. The code that is closed below is correct (C)
a) document.GetelementByidx_x_x_x (mydiv) .style.display = none;
b) document.GetelementByidx_x_x_x (mydiv) .style.display = none;
c) document.Getelementbyidx_x_x_x (mydiv) .style.display = none;
d) document.getelementbyidx_x_x_x (mydiv) .style.display == None;
19. Why use DIV+CSS layout
Form and content separation
Greatly reduce the page code and increase the speed of page browsing
The structure is clear, which is conducive to SEO
Short the revolution time, the layout is more convenient
Design, use multiple times
20. What are the characteristics of block elements? Which elements default
Always start at a new trip;
Height, height, top and bottom distance control;
The width default is 100%of its container, unless set a width
There are elements :,,
,,
What are the characteristics of 21. And inline elements? Which elements belong to the inline element?
Both with other elements are on the line;
High, high and top and bottom margin cannot be changed;
The width is the width of its text or pictures and cannot be changed.
It is inline element:,,,,,,,
,,,
and.
22. What is the result of the expression PARSEINT (x8x8)+pasefloat ('8') in JavaScript? (C)
A) 8+8
b) 88
c) 16
d) 8+ '8
23. The method of the String object does not include (C)
a) Charat ();
b) substring ()
c) length
d) TOUPPERCASE ()
24. About settimeout (Check, 10) The statement is correct (d)
a) Program cycle execution 10 times
b) CHECK function executes every 10 seconds
c) 10 as a parameter passed to the function check
d) CHECK function executes once every 10 milliseconds
25. Which of the following words do not belong to JavaScript keywords: (C)
a) With
b) Parent
c) Class
d) void
Foreword
This article summarizes some high -quality front -end interview questions (mostly from the Internet). After reading, beginners must also study the principles with carefully. Important knowledge requires systematic learning, thorough learning, and forming its own knowledge chain. Do not speculate, just ask for the interview level is wrong!
There are a few points to pay attention to the interview: (Source Cheng Yan Fei Teacher GitHub: @Wintercn)
Interview topic: According to your level and position change, entry -level to expert level: scope ↑, depth ↑, direction ↑.
Types of questions: technical vision, project details, theoretical knowledge questions, algorithm questions, openness questions, case questions.
Questions: You can ensure that you do n’t understand or do n’t understand the interviewer. Because this kind of related knowledge is long -term learning, it is definitely not temporarily remembered.
Answer the question, the interviewer (maybe it is your direct leadership interview), will you consider whether I want this person to be my colleague? So attitude is important. (It feels more like a blind date)
Senior engineers can confuse ABSOLUTE and Relative, so such people don't need it, because you need you as a person who can rely on (reliable).
Outline of the front -end development interview knowledge point:
Html & css:
Understanding of Web standards, browser kernel differences, compatibility, hack, CSS basic skills: layout, box model, selector priority and use, HTML5, CSS3, mobile terminal adaptation adaptation
Javascript:
Data type, object -oriented, inheritance, closure, plug -in, action domain, cross -domain, prototype chain, modularization, custom event, memory leakage, event mechanism, asynchronous loading recovery, template engine, nodejs, JSON, AJAX, etc.
other:
HTTP, security, regular, optimization, reconstruction, response, mobile terminal, team collaboration, maintenance, SEO, UED, architecture, career
As a front -end engineer, the knowledge points that should be mastered regardless of the length of work for the years:
This article was published by Wang Zimo at the front end
1. DOM structure-What are the relationships between the two nodes and how to move arbitrarily between nodes.
2. DOM operation-how to add, remove, move, copy, create, and find nodes.
3. Event-how to use events, and the difference between IE and standard DOM event models.
4. XMLHTTPREQUEST -What is this, how to complete a GET request, how to detect errors.
5. Strict mode and mixed mode-how to trigger these two modes, what does it mean to distinguish them.
6. Box model-the relationship between the outer distance, the inner margin and the border, and the box model in the browser below of IE8
7. Block-level elements and lines in-line-how to control them with CSS and how to use them reasonably
8. Floating elements-how to use them, what problems they have, and how to solve these problems.
9. What is the difference between html and xhtml-two, which one do you think you should use and say a reason.
10. JSON -function, purpose, design structure.