Introduction to JavaScript

The issue with all of this is that the CouchDB callback is asynchronous, and "this.bar" is now within the scope of the callback function, not the class. Does anyone have any ideas for accomplishing what I want to? I would prefer not to have a handler object that has to make the db calls for the objects, but right now I am really stumped with the issue of it being asynchronous.

JavaScript Operators have a predefined order of precedence which are used to process and evaluate a JavaScript expression. JavaScript Operator Precedence is similar to the Mathematical Operator Precedence and Associativity. Like basic algebra Operator Precedence, JavaScript multiplication and division Operator have higher precedence over addition and subtraction Operator.

JavaScript Expression is a combination of values, variables, operators, and functions that are interpreted (evaluated) as per the program logic define(develop) by JavaScript programmer. JavaScript supports a variety of operators like arithmetic, logical and comparison etc. An operator is a function which acts on any number of operands (inputs) to produce a pre-define operation.

JavaScript Reserved KeyWords are part of the JavaScript language syntax. JavaScript Reserved KeyWords has special meanings and used to instruct JavaScript interpreter to perform a specific pre define task. JavaScript has some reserved keywords which can not be used as an identifier. Using JavaScript Reserved KeyWords as an identifier for variable names, function names, and loop labels results in error.

JavaScript Variables are the main building blocks of JavaScript Scripting language. JavaScript Variables are used for storing (contains) the data (value) and manipulate that data in your programs. Every JavaScript variable has a name, called its ‘identifier’ and optional data called ‘Literals’. JavaScript Variables are declared using JavaScript ‘var’ keyword. JavaScript var keyword allocates storage space for variable to store data. Multiple variables can be declared with one JavaScript ‘var’ keyword. The main advantage of JavaScript variable is, it can hold a value of any data type. Using an undeclared variable causes an error. The best practice of defining JavaScript Variables is with assigned initial values.

JavaScript Literals are the notation for representing a fixed data value that appears directly in a JavaScript program. JavaScript Literals helps us to assign values (initialize) to various JavaScript Data Types and Variables; such as integers, floating-point numbers, strings, and Booleans; enumerated Data Types and compound values such as arrays, records, and objects.

JavaScript Comments allows us to add remarks and a well written explanation about the working of JavaScript code. JavaScript Comments make the code more readable, understandable for future reference. Commenting your JavaScript code makes it easier for others to understand. To increase re-usability of a JavaScript code be, sure to include comments in your scripts. Commenting your JavaScript code is the best practice of JavaScript programming and suits to your aspect of good programming style.

A JavaScript statement is a command to a web browser to perform specific task define (program written) by the user. JavaScript Statements are written with the set of elementary rules that specifies how to write JavaScript programs. A JavaScript program is a set of one or more statements. A statement will have internal components like Variables, Literals, Identifier, reserved keywords, Comments, conditional statement, Arrays, Functions, Objects, Classes etc JavaScript is case sensitive, in the most of cases JavaScript Statements terminated with a semicolon(;) or with Returns(Enter or line-break). Even though semicolon is optional, JavaScript Statements terminated with a semicolon(;) is the best practice of JavaScript programming

JavaScript is mostly used as a client-side scripting language. With Client-side JavaScript, we are able to interpreter with the Document Object Model (DOM) of a web browser. On Client-Side, JavaScript add interactive features to your page. JavaScript allowing us to do plenty of tasks on Client-Side like mathematical calculations, form validation, drop down and sliding menus, message tickers, work with events, work with cookies, add special effects and animation, develop interactive games, customize graphics selections, and create security passwords and many more.

JavaScript is most popular, commonly used, object-oriented, client-side scripting language. JavaScript widely used in tasks ranging from the form data validation to the development of enhanced user interfaces and dynamic websites. The primary use of Client-side JavaScript is to write functions that are embedded in or included from HTML pages and interact with the Document Object Model (DOM) of the page. Because JavaScript code can run locally in a user’s browser (instead of get parse on a remote server like PHP or ASP.NET), it can respond to user actions quickly, making an application feel more responsive and user friendly.

The basics of using Javascript functions to execute code or perform commands within your pages.

JavaScript can be difficult to learn on your own. It can be even more difficult to find good tutorials that teach best practices from the onset. I've gathered together 15 video tutorials from the people who really know their JavaScript. You'll learn about the basics of JavaScript and how to debug it from Douglas Crockford, Peter-Paul Koch, Joe Hewitt, and others. This collection of tutorials is for pure JavaScript, no frameworks (those will come in a future post), so you'll get a chance to learn from the ground up.

This is a simple tutorial that introduces people to proper formatting and API usage of jQuery. The tutorial teaches how to use a button to show text in a hidden div tag. There are several other tutorials on the site as well to teach other aspects of jQuery. The goal of the tutorial is that you will be able to understand how to use the API at jquery.com to do anything.

You already know how to define or assign functions directly, use multi parameter arguments in anonymous calls,, know the difference between eval and window.eval - you know all the different variants of the function-constructor? Then you won't find anything new about the subtle differences in using functions in JavaScript.

This tutorial will take you step by step through the fundamentals of Javascript. You will learn how to write functions, create IF-THEN-ELSE conditionals, program loops, and generally make your web page more fun. Some simple cut and paste scripts.

MooTools is a JavaScript library that can be used to manipulate parts of your web page, dynamically transmit data without reloading the page, and it also provides numerous effects, transitions, and user interface tools. This tutorial covers some of the basics for working with MooTools version 1.11, although it should also apply to version 1.2 as well. If you don't know JavaScript yet, you'll pick up many of its basic concepts by reading through to the end.

The following sample of code gives an idea of how to add a blinking flash message at the status bar. Adding flash text at the status is very simple for that we use a single if-else loop in function blinkflash(). This script is compatible with IE. Click here to see live example. First of all we define three variables var message for �display message at status bar�, var speed for �set time interval to flash text�, and var control to control blinking of message

In this tutorial I will show you how to use timeouts in your JavaScript code. With this information you will be able to create a useful timer.

In this tutorial you will learn how to use and manipulate strings in JavaScript.

This Tutorial provides a quick introduction of JavaScript flow control statements. Topics include 'if...then' statements, 'while' statements, 'for' statements, 'break' statements, etc..