web面试25题（Web interview 25 questions）.docVIP

web面试25题（Web interview 25 questions） 1, what is the web standard? The WEB standard is not a standard, but a collection of standards. A web page consists of three main components: structure (Structure), Presentation, and behavior (Behavior). The corresponding standards are also divided into three parts: structured standard language, including XHTML and XML, performance standards language, including CSS, behavior standards, including object models (such as W3C, DOM), ECMAScript and so on. Most of these standards are drafted and published by W3C, and some are standards developed by other standards organizations, such as ECMA (European, Computer, Manufacturers, Association) ECMAScript standards. 2, what is the difference between XHTML and HTML? Which one do you think should be used and give reasons?. The main difference between XHTML1.0 and HTML4.01 is that it complies with the XML encoding convention. Labels cannot overlap and can be nested Both labels and attributes should be lowercase The label should have beginnings and ends, either the end or end in the form of /p, to form br / Each property must have an attribute value, and the attribute value should be in double quotes Dont use name for ID 3, please explain the role of DOCTYPE, there are DOCTYPE and no DOCTYPE what is the difference? The DOCTYPE declaration refers to a line or two line of code at the beginning of the HTML document, which describes which DTD to use. DTD (document type definition) is a group of machine readable rules that define what is allowed in a particular version of XML or HTML, and what is not allowed. When parsing a web page, the browser will use these rules to check the validity of the page and take appropriate measures. The browser knows which DTD to use by analyzing the DOCTYPE declaration of the page, thus knowing which version of HTML to use. DOCTYPE currently has two styles, strict (strict) and transition (transitional). The goal of the transition is to help developers migrate from ol