1. Knowledge and understanding of Web standards and the consortium. (1) Web Standard specification requires that the writing label must be closed, tags lowercase, do not nest, can improve the search robot to search the content of the Web site, (2) recommend the use of the chain of CSS and JS script, so as to achieve the structure and behavior, structure and performance separation, improve the page rendering speed, can quickly display the content of the page; (3) The separation of style and label, more reasonable semantic label, so that content can be accessed by more users, content can be accessed by a wider range of devices, less code and components, thereby reducing maintenance costs, revision more convenient; (4) without the need to change the content of the page, you can provide a print version without copying the content, improve Website usability; Following the Web standards set by the consortium, it makes it easier for users to read and make better communication between Web developers.
What's the difference between 2.xhtml and HTML? HTML is a basic Web page design language, XHTML is an xml-based markup language; The main difference: XHTML elements must be nested correctly. XHTML elements must be closed. Label names must be in lowercase letters. XHTML documents must have root elements.
3.Doctype? Strict and promiscuous mode-how do you trigger both patterns, and what is the point of distinguishing them? Used to declare a document using that specification (html/xhtml) typically adds an XML declaration to a strictly overly framework-based HTML document to trigger, parsing to IE5.5 owning IE5.5 bugs
4. What are the elements in the inline? What are the block-level elements? The box model of CSS? Block-level elements: div p H1 H2 H3 h4 form UL inline elements: A b br i span input select CSS box model: Content, Border, margin,padding
What are the methods of 5.CSS introduction? What's the difference between link and @import? Inline inline outer chain import difference: While loading the former without compatibility, the latter CSS2.1 the following browsers do not support link support using JavaScript to change styles, which cannot
What are the 6.CSS selectors? Which attributes can inherit? How does the priority algorithm calculate, inline and important? Which priority is higher? Tag Selector class selector Id selector inheritance as specified id>class> label Select the latter priority high
7. What are the three layers of the front page? What is the function? Structure Layer Html Presentation layer CSS behavior Layer JS
What is the basic sentence composition of 8.css? Selector {Property 1: Value 1; Property 2: Value 2; ...}
9. What browser do you have to test? What are the cores of these browsers? IE (ie kernel) firefox (Gecko) Google (WebKit) opear (Presto)
10. Write out several solutions to the IE6 Bug 1. Use of Display:inline 2.3 pixel problem caused by double offset bug float dislpay:inline-3px or margin-right:-3px 3. Link hover after clicking Invalid use the correct writing sequence link visited hover active; 4.Ie z-index problem to add position:relative to the parent, 5.Png transparent use JS code change; 6.min-height most Small height. Important resolution ' 7.select under IE6 cover using IFRAME nesting; 8. Why there is no way to define the width of the container around 1px (IE6 default row height caused by the use of over:hidden,zoom:0.08 line-height : 1px);
11. What is the difference between the title and the Alt attribute on the label? The ALT attribute is the message that appears on the page when your picture is not loaded for some reason. It will output directly to the place where the picture was originally loaded; The Title property is a small hint when you hover over the picture, the mouse is gone, a bit like the hover of jquery, You can try it on your own, in addition, most of the HTML tags support the title attribute, Title attribute is specifically to do the hint information;
12. Describe the role and use of CSS reset. Reset resets the browser's CSS default properties, the browser variety, different styles, and then reset, let them unified. For example (there is the simplest *{margin:0; padding:0});
13. Explain CSS sprites, how to use. The CSS Wizard consolidates a bunch of small pictures into a large picture, reducing the number of requests to the picture from the server;
14. What is the difference between browser standard mode and weird mode? The so-called standard mode is that the browser according to the standard of the web to parse the execution code; The weird pattern is to parse the execution code in its own way, because different browsers parse the execution differently, so we call it weird mode. Does the browser use standard or weird mode when parsing? Directly related to the DTD declaration in your Web page, the DTD declaration defines the type of the standard document (Standard mode resolution) document type, which causes the browser to load the Web page and display it in the appropriate way, ignoring the DTD declaration, and putting the page into a weird mode (quirks mode). Different use of box model rendering mode Window.top.document.compatMode can show why mode
15. How do you optimize your Web site's files and resources? Expected solutions include: file merge file minimization/file compression use of CDN managed caching
16. What is semantic HTML? Semantic HTML is the HTML code that is written, conforms to the content of the structure (content semantics), select the appropriate tags (code semantics), can facilitate the developer to read and write more elegant code, while the browser's crawler and machine to resolve well. 1. Semantics is advantageous to the SEO, is advantageous to the search engine crawler better understanding our webpage, thus obtains the more effective information, the enhancement webpage weight. 2. In the absence of CSS can clearly see the structure of the Web page, enhance readability. 3. Facilitate team development and maintenance, semantic HTML can make it easier for developers to understand, thereby improving the team's efficiency and coordination capabilities. 4. Support for multiple terminal equipment browser rendering. (Summary: Intuitive understanding of the tag for search engine capture is good)
17. Remove the floating of several ways, their respective advantages and disadvantages 1. Use empty tags to clear floating clear:both (theoretically clear any label, add meaningless tags) 2. Use Overflow:auto (empty tag elements to clear the float and have to increase the abuse of unintentional code, Use Zoom:1 for compatible IE) 3. Clear float with Afert pseudo element (for non IE browsers)
Javascript 1.javascript typeof returns which data types Object, number, function, Boolean, Underfind, string
2. Examples of 3 coercion and 2 implicit type conversions? Force (Parseint,parsefloat,number) implicit (==–===)
3.split () join () the difference Split () method: Used to split a string into an array of strings. The join () method is used to put all elements in an array into a string. (Summary: The former is the form of cutting into groups, the latter is to convert the array to a string);
4. Array method Pop () push () unshift () Shift () push () tail add; pop () tail delete; Unshift () head add; Shift () head delete;
5. What is the difference between event binding and ordinary events? An event binding is an event for a DOM element, and a normal event bound to a DOM element is an event that is not a DOM element; For example: Ordinary event var btn = document.getElementById ("Hello"); Btn.onclick = function () {alert (1);}; Btn.onclick = function () {alert (2);}; This event will only pop up 2;
Event binding var btn = document.getElementById ("Hello"); Btn.addeventlistener ("click", Function () {alert (1);},false); Btn.addeventlistener ("click", Function () {alert (2);},false); This event pops up 1 First and then pops up 2;
The difference between 6.IE and DOM event streams. 1. The order of execution is different; 2. Parameters are not the same; 3. event Plus no on; 4.this Point;
7.IE and what compatibility is written under the standard Var ev = EV | | Window.event Document.documentElement.clientWidth | | Document.body.clientWidth Var target = ev.srcelement| | Ev.target
8.ajax request, the difference between get and post methods. 1, get is to add the parameter data queue to submit the form of the action attribute refers to the URL, the value and the form of each field one by one corresponds, in the URL can be seen; Post is the HTTP post mechanism that places the fields in the form and their contents in HTML The header is routed together to the URL address that the action attribute refers to. The user does not see this process; 2. The GET request has the following characteristics: It adds data to the URL, which is passed to the server in this way, usually using a question mark. Represents the end of a URL address and the beginning of a data parameter, with each data parameter in the form of a "name = value", which is differentiated between parameters and parameters using a connector &. Post requests have the following characteristics: The data is placed in the HTTP body, the organization of more than one, there are & connection, but also have the way of dividing, can hide parameters, transfer a large number of data, more convenient. 3, get transmitted data volume is small, can not be greater than 2KB, post transfer of large amount of data, generally default to unrestricted. In theory, however, it varies depending on the server. 4, get security is very low, post security is high; (Summary: One in the URL behind a virtual carrier has a size limit security problem application is a forum, etc. only need to request, one is similar to modify the password)
The difference between 9.call and apply. Same point: Two methods produce exactly the same different points: The method passed by different object.call (THIS,OBJ1,OBJ2,OBJ3) calls one method of an object, replacing the current object object.apply with another object (this, Arguments) applies a method of an object and replaces the current object with another object.
10.ajax request, how to interpret JSON data. Using the Eval parse parse is more reliable in view of security considerations
11.b inherits the method of a. B.prototype=new A;
12. Write a function that gets a non-row style GetStyle (obj,attr,value) {if (!value) {if (Obj.currentstyle) {return Obj.currentstyle (attr)} else{Obj.getcomputedstyle (Attr,false)}}else{Obj.style[attr]=value}}
13. What is the event delegate? Let's use the principle of event bubbling to let his own trigger event, and let his parent element replace execution. An event delegate is the event target itself does not handle the event, but instead delegates the processing task to its parent element or ancestor element, or even the root element (document), which is provided by jquery for binding and delegate events. Bind (),. Live () and. Delegate () method; http:// The Www.tuicool.com/articles/zQVvau example shows this link
14. What is the closure, what is the characteristics of the page has any impact. Closures are functions that can read internal variables of other functions. http://blog.csdn.net/gaoshanwudi/article/details/7355794 this link to view (not a company to ask this question)
15. How to block event bubbling and default events. Cancebubble return false View http://www.2cto.com/kf/201412/359961.html case
16. Add Delete Replace insert to a point method. Obj.appendchidl () Obj.innersetbefore obj.replacechild obj.removechild
17. Explain the principles of JSONP and why it is not real Ajax. Dynamically create script tags, callback function ajax is page no refresh request data operation
18.javascript of local objects, built-in objects, and host objects. Local object for array obj regexp can be new to instantiate built-in objects for Gload Math and so on that cannot be instantiated by hosting the browser-brought Document,window
19.document the difference between load and document ready. Document.onload is in the structure and style after loading to perform js document.ready native species without this method, jquery has $ (). Ready (function)
20. What is the difference between "= =" and "= ="? The former will automatically convert the type the latter will not
21.javascript's homology strategy? A script can only read properties from Windows and documents from the same source, where the same source refers to a combination of host names, protocols, and port numbers
22. Write an array to weight the method. 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}
The article should be from others to turn out, but at that time directly saved to the Youdao, has forgotten the source, hope to see the original forgive
