Today, this article introduces some basic concepts and technologies used in web development to beginners. There are 26 items in total from A to Z, each corresponding to a concept or technology.
A — AJAXAJAX is full name Asynchronous JavaScript and XML (asynchronous JavaScript and XML), and is a web development technology that creates interactive web applications. According to the suggestion of Ajax proposer Jesse James Garrett, AJAX:
Use XHTML + CSS to represent information;
Use JavaScript to operate the DOM (Document Object Model) for dynamic display and interaction;
Use XML and XSLT for data exchange and related operations;
Use the XMLHttpRequest object to exchange asynchronous data with the web server;
Use JavaScript to bind everything together.
Similar to DHTML or LAMP, AJAX does not refer to a single technology, but organically utilizes a series of related technologies. In fact, some derivative/composite technologies based on AJAX are emerging, such as AFLAX.
B — Browser
A web browser is a software that displays files in a web server or file system and allows users to interact with these files. It is used to display text, images and other information on the World Wide Web or LAN. These text or images can be hyperlinks connecting to other URLs, and users can quickly and easily browse various information. Most web pages are in HTML format, and some web pages require specific browsers to display correctly. The common web browsers on personal computers are Microsoft's Internet Explorer, Mozilla's Firefox, Google's Google Chrome, Apple's Safari and Opera's Software's Opera. Browsers are the most commonly used client programs. Web developers should make sure their programs work properly in all mainstream browsers.
C — CSS
Cascading style sheets, also known as: string style list, English: Cascading Style Sheets, abbreviated as CSS, a standard defined and maintained by W3C, a computer language used to add styles (fonts, spacing, and colors, etc.) to structured documents (such as HTML documents or XML applications). The latest version is CSS 2.1, which is a candidate recommendation standard for W3C. The next version of CSS 3 is still in development.
D — DOM
Document Object Model (DOM) is a standard programming interface recommended by W3C organizations to handle extensible markup languages. Document Object Model can be traced back to the browser wars between Microsoft and Netscape in the late 1990s. In order to fight life and death with JScript in JavaScript, the two sides gave the browser powerful functions on a large scale. Microsoft has added many exclusive things to web page technology, including VBScript, ActiveX, and Microsoft's own D HTML format, which makes many web pages unable to display normally using non-Microsoft platforms and browsers. DOM is a masterpiece that was brewed at that time.
E — Events
Events are operations that can be recognized by the control, such as pressing the OK button and selecting a radio button or check box. Each control has its own events that can be recognized, such as the loading, clicking, double-clicking of the form, the text of the editing box (text box) changes things, etc. Modern web applications rely heavily on event-driven.
Events include system events and user events. System events are triggered by the system, such as every 24 hours, the deposit date of bank depositors increases by one day. User events are triggered by users, such as if the user clicks a button to display specific text in the text box. The event-driven control performs a function. The object that triggers the event is called the event sender; the object that receives the event is called the event receiver.
It can be achieved using the event mechanism: when a certain state of the class object changes, the system will call the method in the class for handling this event through some way or the object that triggers the control event will call all registered event handlers of the control, etc.
F — Firebug
Firebug is an extension of the web browser Mozilla Firefox and is a debugging tool. Users can use it to debug, edit, or even delete CSS, HTML, DOM, and JavaScript code of any website. Firebug also provides other web development tools, such as Yahoo!'s web speed optimization suggestion tool YSlow. Firebug is written by Joe Hewitt. He was one of the original founders of Firefox.
G — Grid
Grids, also known as rasters, but by definition, rasters are more accurate. Find a more appropriate definition of web page grid system on the Internet: use a regular grid array to guide and standardize the layout and information distribution in web pages. Web raster systems are developed from planar raster systems. For web design, the use of grid systems can not only make the information on web pages more beautiful and easy to read, but also more usable. Moreover, for front-end development, web pages will be more flexible and standardized. If there are many CSS frameworks that support grid function, you can refer to the article "Introduction to 27 Classic CSS Frames".
H — HTML
HyperText Markup Language (HTML) is a markup language designed for web page creation and other information that can be seen in web browsers. HTML is used to structure information - such as titles, paragraphs, lists, etc., and can also be used to describe the appearance and semantics of a document to a certain extent. The original definition given by Tim Berners-Lee, further developed by the IETF with the simplified SGML (standard universal markup language) syntax, later became an international standard and maintained by the World Wide Web Consortium (W3C).
The latest version is HTML5 It is the next major revision of HTML and is still in its development stage. The goal is to replace the HTML 4.01 and XHTML 1.0 standards set in 1999, in order to enable the network standards to meet contemporary network needs when Internet applications are developing rapidly. When talking about HTML5 in general, it actually refers to a set of technology combinations including HTML, CSS and JavaScript.
I — IE
Windows Internet Explorer (formerly known as Microsoft Internet Explorer, referred to as Internet Explorer, abbreviated as IE), is a web browser launched by Microsoft. As of September 2010, statistics show that Internet Explorer's market share is as high as 59.65%. Although it remains the most widely used web browser, its market share is more than 30% different from its peak in 2003.
Internet Explorer has some support for some standardized technologies, but there are also many operational gaps and compatibility failures, which has led to increasing criticism from technology developers. The increase in criticism is largely due to the relatively complete technical support of Internet Explorer competitors, and the application of standard specifications (Standards-compliant) is becoming increasingly widespread. Because Internet Explorer is widely used around the world, web developers often find vulnerabilities in Internet Explorer, private collections of features and incomplete standards when seeking cross-platform code.
The Internet Explorer 9 browser released on March 14, 2011 significantly increased its support for W3C specifications such as CSS3 and HTML5. This version is also the first version of Internet Explorer browser to adopt GPU acceleration. The official version scored 95/100 points in the Acid3 test, which is a great improvement compared to previous versions. It can be believed that starting with Internet Explorer 9, the support for W3C specifications by Internet Explorer browser will no longer be a problem.
J — JavaScript
JavaScript is a scripting language widely used in client web development. It is often used to add dynamic functions to HTML web pages, such as responding to various user operations. Originally designed by Netscape's Brendan Eich, it is a dynamic, weak type, prototype-based language with built-in support classes. JavaScript is a registered trademark of Sun Company. Ecma International has formulated the ECMAScript standard based on JavaScript. JavaScript can also be used in other occasions, such as server-side programming. The complete JavaScript implementation consists of three parts: ECMAScript, document object model, byte order notation.
Netscape initially named its scripting language LiveScript to Netscape renamed it JavaScript after working with Sun. JavaScript was originally designed inspired by Java, and one of the purposes is to look like Java, so there are similarities in syntax, and some names and naming specifications are also borrowed from Java. However, the main design principles of JavaScript come from Self and Scheme. The similarity between JavaScript and Java names was the result of Netscape reaching an agreement with Sun for marketing considerations at that time. In order to gain technical advantages, Microsoft launched JScript to fight JavaScript's scripting language. For interoperability, Ecma International (formerly the European Association of Computer Manufacturers) created the ECMA-262 standard (ECMAScript). Both are now part of the implementation of ECMAScript. Although JavaScript is promoted and promoted as a scripting language for non-programmers, not as a programming language for programmers, JavaScript has very rich features.
K — Keyword Optimization
Keyword optimization, also known as search engine optimization (SEO), is a way to use search engine search rules to improve the ranking of the target website in relevant search engines. Since many studies have found that search engine users often only pay attention to the first few entries in the search results, many websites hope to influence the sorting of search engines through various forms. Among them, there are many websites that rely on advertising to make a living.
The so-called optimization of search engines refers to making the website easier to be accepted by search engines. Search engines will compare the content of the websites with some correlation data, and then the browser will reflect the content to the searcher in the fastest and most comprehensive way.
Search Engine Optimization For any website, search engine optimization is a crucial task to succeed in website promotion. At the same time, as search engines continue to change their ranking algorithm rules, each algorithm change will cause some well-ranked websites to fail overnight, and the direct consequence of losing ranking is to lose the considerable number of visits inherent to the website. Therefore, every time the search engine algorithm changes, it will cause a lot of commotion and anxiety in the website. It can be said that search engine optimization is an increasingly complex task.
L — Less
Less was originally a ruby gem, which gave CSS the characteristics of a dynamic language, including variables, operators, and nested rules. In fact, Less' real function is to convert CSS using advanced features into standard CSS. These are done through the Http Handler when the web client initiates the request. It can also be done at editing. In addition, Less can be configured to automatically minimize the generated CSS files, not only saving bandwidth but also taking the end user experience to the next level. There is also the .Net version of Less.
M — MVC
MVC mode (Model-View-Controller) is a software architecture model in software engineering, which divides the software system into three basic parts: model (Model), view (View) and controller (Controller). The MVC model was first proposed by Trygve Reenskaug in 1974. It is a software design model invented by Xerox PARC for the programming language Smalltalk in the 1980s. The purpose of the MVC model is to implement a dynamic programming, simplify subsequent modifications and extensions of the program, and make it possible to reuse a certain part of the program. In addition, this mode makes the program structure more intuitive by simplifying the complexity. The software system separates its basic parts while also giving each basic part the functions it deserves.
N — Node.JS
Node is a Javascript runtime, which actually encapsulates the Google V8 engine (applied to Google Chrome). The V8 engine executes Javascript very quickly and has very good performance. Node optimizes some special use cases and provides alternative APIs to make V8 run better in non-browser environments. For example, in a server environment, processing binary data is usually essential, but Javascript does not support this, so V8.Node adds a Buffer class to process binary data conveniently and efficiently. Therefore, Node not only simply used V8, but also optimized it to make it more powerful in various environments. Node.js is all-encompassing, but the most important thing is that it provides a way to run Javascript outside of a web browser. Javascript is widely used in front-end development of websites. Node allows this popular programming language to run in more environments, even on the server side of the website.
O — Object
Object is a term in object-oriented (Object Oriented), which not only represents a specific thing in the objective world problem space (Namespace) and also represents the basic elements in the software system solution space. In a software system, an object has a unique identifier, and the object includes properties (Properties) and methods (Methods). The attribute is the information that needs to be remembered, and the method is the services that the object can provide. In object-oriented software, an object is an instance of a certain class.
P — PHP
PHP (H ypertext P reprocessor) is a scripting language that runs on a computer. Its main purpose is to handle dynamic web pages, and it also includes a command line interface, or generates a graphical user interface (GUI) program. PHP was first invented by Rasmus Lerdorf in 1995, and now the PHP standard is maintained by the PHP Group and the open source community. PHP uses PHP License as the license agreement, but because this agreement limits the use of PHP names, it is incompatible with the open source license agreement GPL.
PHP has a wide range of applications, especially in the development of web programs. Generally speaking, PHP is mostly run on a web server, and the web pages that users browse by running PHP code. PHP can run on most servers and operating systems, and using PHP is completely free. According to statistics in April 2007, PHP has been installed on more than 20 million websites and 1 million servers.
Q — Query
Query has many meanings. For example, query languages are used to interact with extended systems that store data. A good example is SQL for operating relational databases. Another meaning is that a query string is used as part of the URL to pass data in a web application. The format of the query string is generally in the form of a key-value pair.
R — Regular Expressions
Regular expression (English: Regular Expression, regex or regexp, abbreviated as RE), is also translated as regular representation and conventional representation. In computer science, it refers to a single string used to describe or match a series of strings that conform to a certain syntactic rule. In many text editors or other tools, regular expressions are often used to retrieve and/or replace text content that conforms to a certain pattern. Many programming languages support string manipulation with regular expressions. For example, a powerful regular expression engine is built in Perl. The concept of regular expression was originally popularized by tool software in Unix (such as sed and grep).
S — Source Control
Source code management, also known as version control, is a software engineering technique that can ensure that the same program files edited by different people are synchronized during the software development process. Software designers often use version control to track, maintain source code, files, and settings, etc., and provide programs that control these changes. In the simplest case, software designers can keep many different versions of a program themselves and number them appropriately. This simple method has been used in many large-scale software projects. This is a way to achieve the purpose, but not efficient enough. In addition to maintaining a lot of almost the same code backups at the same time, it also relies heavily on the self-cultivation and development discipline of software designers, but this is often the cause of errors.
Sometimes, it is necessary for a program to have more than two versions at the same time. For example, in one version for deployment, the program error has been fixed, but no new features have been added; in the other version, new functions are being developed and new errors are to be resolved, which makes different versions and modifications are required at the same time. In addition, in order to find out the program errors that exist only in a specific version, or to find out the versions where the program error occurs, software debuggers must also compare different versions of the program code to find out the location of the problem.
T — TDD
Test-driven development is a method of modern computer software development. Use tests to drive the design and implementation of software programs. Test drivers became popular in the 1990s. Test-driven development is a program development method advocated in extreme programming. The method mainly involves writing the test program first and then encoding it to pass the test. The purpose of test-driven development is to get quick feedback and use the illustration the main line method to build the program.
A metaphor for testing-driven development. Development can be viewed from two aspects: the function and quality of implementation. Test-driven development is more like the development method of thinking about two hats. First, wear the hat to implement functions, and quickly realize the correct functions with the assistance of testing; then wear the hat to refactor, and under the protection of testing, improve code reusability and achieve quality improvements by removing redundant and duplicate code. It can be seen that testing does have a core position in test-driven development and runs through the development.
U — Unit Testing
Unit testing (also known as module testing) is a test that conducts correctness verification for program modules (the smallest unit of software design). The program unit is the smallest testable component for the application. In procedural programming, a unit is a single program, function, procedure, etc.; for object-oriented programming, the smallest unit is a method, including methods in base classes (superclasses), abstract classes, or derived classes (subclasses).
Generally speaking, programmers will conduct at least one unit test every time a program is modified. It is likely that multiple unit tests will be conducted before and after the program is written to confirm that the program meets the work goals required by the software specification book (en:Specification) and does not have bed bugs; although unit testing is not necessary, it is not bad, which involves policy decisions in project management.
V — VIM
Vim is a text editor developed from vi. Code completion, compilation and error jumping are particularly rich in programming functions and are widely used among programmers. It is parallel to Emacs and becomes the favorite editor for users of Unix-like system systems. The first version of Vim was released in 1991 by Bram Moolenaar. The original abbreviation was Vi IM itation. With the continuous increase in functions, the official name was changed to Vi IM proved. Now it is free software released in open source.
W — WordPress
WordPress is a blog platform developed using the PHP language. Users can set up their own blogs on servers that support PHP and MySQL databases. You can also use WordPress as a content management system (CMS). WordPress is a free open source project licensed under the GNU General Public License. The latest version is the official simplified Chinese version of 3.0.5 released on February 24, 2011, and there are also multiple languages that include English.
X — XSS
Cross-site scripting ( often referred to as XSS ) is a security vulnerability attack for website applications that allows malicious users to inject program code into web pages, and other users will be affected when viewing web pages. This type of attack usually includes HTML and user-side scripting languages.
Y — YUI
Yahoo! UI Library (YUI) is an open source JavaScript function library. In order to create a highly interactive web page, it uses AJAX, DHTML and DOM and other programming technologies. It also contains many CSS resources.
Z — Z index
Z-Index
It is a CSS attribute that sets the stacking order of elements. Elements with higher stacking order will always be in front of elements with lower stacking order. This property sets the position of a positioning element along the z-axis defined as the axis extending vertically to the display area. If it is a positive number, it is closer to the user, and if it is a negative number, it means it is farther away from the user.