JavaScript Language | 30 Minute Test 7

All these facilities are available in JavaScript. Additionally, all development environments provide syntax to create and use memory variables, constants, and functions.

JavaScript code is as easy to be implemented and run. It can be called by using a function or a method.

None.

JavaScript is not a full-blown OOP (Object-Oriented Programming) language, such as Java or PHP, but it is an object-based language.

The do/while loop is less commonly used when compared to the while loop. Here, it prints from the array in the given order.

An object is an unordered collection of properties, each of which has a name and a value. Property names are strings, so we can say that objects map strings to values.

If you omit a value from an array literal, the omitted element is given the value.

The function definitions begin with the keyword function followed by an identifier that names the function and a pair of parantheses around a comma-separated list of zero or more identifiers.

Even if the string value passed as a parameter to eval does represent a numeric value the use of eval() results in an error being generated.

Like most modern programming languages, JavaScript uses lexical scoping. This means that functions are executed using the variable scope that was in effect when they were defined, not the variable scope that is in effect when they are invoked.

The behaviour of the instance of a class is defined by the class and is shared by all instances

The four kinds of class members are Instance fields, Instance methods, Class fields, Class methods.

Both the Dojo toolkit and Google’s Closure library define provide() and require() functions for declaring and loading modules.

The ‘S’ is a special metacharacter that matches the end of a string.

The Crockford’s subset does not include the with and continue statements or the eval() function. It defines functions using function definition expressions only and does not include the function definition statement.

The above code snippet will flash an error. Attempts to alter the value or re-declaration causes errors.

The functions defined in this way behave exactly like functions defined with curly braces and the return keyword.

Node objects that generate events (known as event emitters) define an on() method for registering handlers.

Rhino is free software from Mozilla. You can download a copy from http://www.mozilla.org/rhino/.

Node is a fast C++-based JavaScript interpreter with bindings to the low-level Unix APIs for working with processes, files, network sockets, etc., and also to HTTP client and server APIs.

The various forms of client-side storage are web databases, filesystem API, Offline web applications and cookies.

The Client-side JavaScript code is embedded within HTML documents in four ways :
1.Inline, between a pair of “script” tags
2.From an external file specified by the src attribute of a “script” tag
3.In an HTML event handler attribute, such as onclick or onmouseover
4.In a URL that uses the special javascript: protocol.

Some pages present static information and can be called documents.

The first child of a node can be accessed using the firstChild property.

Many web developers find it useful to build their web applications on top of a clientside framework library. These libraries are “frameworks” in the sense that they build a new higher-level API for client-side programming on top of the standard and proprietary APIs offered by web browsers: once you adopt a framework, your code needs to be written to use the APIs defined by that framework.

setTimeout() and setInterval() allow you to register a function to be invoked once or repeatedly after a specified amount of time has elapsed.

The Document object has a URL property, which is a static string that holds the URL of the document when it was first loaded.

The above code snippet goes back 2, like clicking the Back button twice.

A single web browser window on your desktop may contain several tabs. Each tab is an independent browsing context.

The Document object does not stand alone, however. It is the central object in a larger API, known as the Document Object Model, or DOM, for representing and manipulating document content.