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The correct option is (b) Two objects reference

To ELABORATE: Old versions of Internet EXPLORER COULD not detect cyclic references between DOM NODES and JavaScript code. A cycle happens when two objects reference each other in such a way that both objects retain each other.

The correct ANSWER is (d) All of the mentioned

Easy explanation: The primary purpose of a destroy FUNCTION is to centralize the responsibility for cleaning up anything that the object has done that will:

Prevent its reference count from dropping to 0 (for example, REMOVING problematic event listeners and callbacks and unregistering from any services).

Consume unnecessary CPU cycles, such as INTERVALS or ANIMATIONS.

Right ANSWER is (b) Must have the same origin

The best explanation: If you specify an ABSOLUTE URL, it must have the same origin (same protocol, host, and port) as that containing document. In Firefox, if you WANT to use workers in extensions and would like to have access to js-ctypes, you should use the ChromeWorker OBJECT instead.

Correct answer is (d) Only Open source and Web APPLICATION

Easiest explanation: Closure COMPILER parses your JavaScript, analyzes it, REMOVES dead code and rewrites and minimizes what’s left. You can USE the Closure Compiler as:

An open source Java application that you can run from the command line.

A SIMPLE web application.

A RESTful API.

Right CHOICE is (c) Run the code

For explanation: The startTimeLogging() method CAPTURES the timing data for AD HOC, etc for referencing an uncached document.location. Once the startTimeLogging() method is CALLED, run the code to test.

The correct option is (d) To cache the REFERENCE DOCUMENT.location

To EXPLAIN: window.location.assign LOADS a new document. The locally scoped VARIABLES are created to cache the reference to document.location.

The correct option is (b) Shape and coordinates of the hotspot

The EXPLANATION is: The tag defines an area INSIDE an image-map (an image-map is an image with clickable areas). The ELEMENT is always NESTED inside a

The correct ANSWER is (d) All of the mentioned

Easiest EXPLANATION: JavaScript animations are done by programming gradual changes in an element’s style. You can use JavaScript to CREATE a complex ANIMATION which includes but not LIMITED to:

Fireworks

Fade Effect

Roll-in or Roll-out

Page-in or Page-out

Object movements.

The correct choice is (B) HTML Attribute

The best I can explain: When a WEB page is LOADED, the browser CREATES a Document Object Model of the page. In the HTML DOM, the Attr object represents an HTML attribute.

Right option is (C) Both Renames variables and function

Easiest EXPLANATION: In Advanced MODE it rewrites the JavaScript by renaming variables and functions from longer descriptive names to single LETTERS to save file SIZE, and it inlines functions, coalescing them into single functions wherever it determines that it can.

Right OPTION is (b) Mere data existence

Easy explanation: The data entered through the SERVER side is USED for VALIDATION. First of all, the form must be checked to make sure data was entered into each form field that required it. This would need just loop through each field in the form and check for data.

Correct choice is (B) Sets ATTRIBUTE node

Explanation: The setNamedItem() method adds the SPECIFIED node to the NamedNodeMap. The method nodeMap.setNamedItem() sets the specified attribute node (by name).

Right option is (c) BlobBuilder

Explanation: BLOBS represent data that isn’t NECESSARILY in a JavaScript-native format. You can create your own blobs, USING a BlobBuilder OBJECT to build them out of strings, ARRAYBUFFER objects, and other Blobs.

Correct OPTION is (a) FILE type to be expected

Explanation: The File.type PROPERTY is an inbuilt FUNCTION of File WebAPI which gives the media type (MIME) of the file REPRESENTED by a file object. The function parameter “filetype” lets you tell the script what file type to expect before loading.

Right CHOICE is (d) slice()

Explanation: The File interface is based on Blob, inheriting blob functionality and expanding it to support files on the user’s system. The web browser can store Blobs in memory or on DISK, and Blobs can represent REALLY enormous chunks of data (such as video files) that are too large to fit in main memory without FIRST being broken into smaller PIECES with slice().

The correct answer is (c) EITHER ABSOLUTE or Relative

Best explanation: The PHP code is enclosed in special start and end PROCESSING instructions that allows you to jump into and out of “PHP MODE”. The PHP file is either an absolute or relative PATH to a PHP script instead of the usual .js file.

Correct choice is (a) user_pref(“javascript.console.open_on_error”, true);

EXPLANATION: The prefs.js file, located in the profile FOLDER, is used by FIREFOX and other Mozilla-based applications to store settings. For instance, when you create a NEW e-mail account in Thunderbird, the account NAME and server settings will be stored in the prefs.js file in your Thunderbird profile folder.

The code :

The correct option is (d) value

Explanation: Plugins are reusable portions of code which help you write EVEN LESS Javascript to achieve specific features on the client side. Each plug-in has an ENTRY in the ARRAY. Each entry has the following properties:

name – is the name of the plug-in.

filename – is the EXECUTABLE file that was loaded to install the plug-in.

description – is a description of the plug-in, supplied by the developer.

mimeTypes – is an array with one entry for each MIME type supported by the plug-in.

Right choice is (c) both setTimeout and setInterval

Easiest explanation: setTimeout(function, milliseconds) EXECUTES a function, after waiting a specified number of milliseconds. FUNCTIONS USED in setTimeout/setInterval are REFERENCED INTERNALLY and tracked until complete, then cleaned up.

Right OPTION is (d) Nowhere

To explain I WOULD say: window.location.assign loads a NEW DOCUMENT. During the traversal in the stack manner, after going to the window, it goes nowhere.

The correct CHOICE is (a) Single-threaded

The best explanation: In computer programming, single-threading is the PROCESSING of ONE COMMAND at a time. One of the fundamental features of client-side JavaScript is that it is single-threaded: a browser will never RUN two event handlers at the same time, and it will never trigger a timer while an event handler is running.

The correct choice is (d) no predefined FUNCTION for DATA VALIDATION

The best explanation: There is no such function to validate a data but, you can WRITE a function with any name to validate the data. Hence there is no predefined function for data validation.

The CORRECT choice is (C) Sends back the data and Waits for correction

To explain I would say: The only way to obtain data is from the server SIDE which is used to perform further operations on the data. If some of the data that had been entered by the CLIENT had been in the wrong form or was simply MISSING, the server would have to send all the data back to the client and request that the form is resubmitted with correct information.

The correct option is (a) onMouseOver

For explanation I would say: The onmouseover attribute FIRES when the MOUSE pointer MOVES over an element. The onmouseover attribute is OFTEN used together with the onmouseout attribute.

The correct answer is (B) Describe particular task

To elaborate: In COMPUTER programming, an application programming interface is a SET of subroutine definitions, communication protocols, and TOOLS for building software. An API may describe the ways in which a particular task is performed.

The CORRECT ANSWER is (b) src

For EXPLANATION: Php FILE is used an scripting language for backend development. The syntax to REFERENCING a PHP file using external JavaScript is consistent enough with what we already know:

Right ANSWER is (a) Browser doesn’t release MEMORY from objects unnecessary

For explanation I would say: Memory leaks happen when your CODE needs to consume memory in your application, which should be RELEASED after a given task is complete but isn’t. Memory LEAK happens when the browser for some reason doesn’t release memory from objects which are not needed any more.

Correct answer is (a) ONLOAD

Easiest explanation: One of the most important event handlers is the onload handler of the Window object. It is TRIGGERED when the content of the document DISPLAYED in the window is stable and ready to be manipulated. JAVASCRIPT code is commonly WRAPPED within an onload event handler.

The correct option is (a) Content is played

For explanation I would SAY: The event onAirEvent is fired when the PLAYER starts playing content being broadcasted on the channel. The METHOD is CALLED at the time of the creation of adspace.

The correct answer is (d) $HTTP_GET_VARS[]

Explanation: The global variable $HTTP_GET_VARS[] is used to GET PARAMETERS. $HTTP_GET_VARS CONTAINS the same initial information, but is not a SUPERGLOBAL.

The correct answer is (C) PHP

To EXPLAIN I would say: PHP (RECURSIVE acronym for PHP: Hypertext Preprocessor) is a widely-used open source general-purpose scripting language that is especially suited for web development and can be embedded into HTML. One of the LESSER known sides of external JavaScript is the ability to reference a PHP file INSTEAD of the familiar .js file.

Correct answer is (c) Bytes

The explanation: A Blob object represents a file-like object of immutable, RAW DATA. Blobs represent data that isn’t necessarily in a JavaScript-native FORMAT. Blobs are opaque all you can do with them DIRECTLY is determine their size in bytes, ask for their MIME type, and chop them up into smaller Blobs.

The CORRECT choice is (c) Both Memory and Disk

The explanation: A Blob object represents a file-like object of immutable, raw data. The WEB BROWSER can store BLOBS in memory or on disk, and Blobs can represent really enormous chunks of data (such as video files) that are too large to fit in MAIN memory without first being broken into smaller pieces with slice().

The correct answer is (c) Traverses the stack

For explanation: window.location.href returns the href (URL) of the current PAGE. If you REFERENCE DOCUMENT.location from within an object, the interpreter will need to go from the FUNCTION that references the VARIABLE, up out of the namespace to the global window scope, down to the document scope, and gets the location value.

Correct choice is (c) map

The best I can explain: The usemap attribute is associated with a

Correct answer is (b) Allows access to few keys and ELEMENTS

Best explanation: The Legacy DOM: This is the model which was introduced in early versions of JavaScript language. It is well SUPPORTED by all browsers but allows access only to CERTAIN KEY portions of documents, such as forms, form elements, and images.

Correct option is (b) FOCUS()

The best I can EXPLAIN: The focus() FUNCTION can be used to focus a particular part of the HTML page in JavaScript. It sets the ELEMENT as the active element in the current document. It can be applied to one html element at a single time in a current document.

The correct OPTION is (c) indexOf()

The explanation: The indexOf() FUNCTION can be used to find out the INDEX of a particular character or a string. This method return an INTEGER telling the address of the particular character.

Correct answer is (d) UNORDERED COLLECTION of arrays

For explanation: In the HTML DOM, the NamedNodeMap object represents an unordered collection of an elements attribute nodes. The nodes in the NamedNodeMap can be ACCESSED through their NAME.

The correct choice is (a) .js

To elaborate: JavaScript supports EXTERNAL JavaScript, in the form of .js file. This extension can be CAPTURED by a number of applications including: Windows Script Host, DREAMWEAVER MX, Notepad, Netscape Navigator, PavScrip, UltraEdit. The files are generally text files.

The correct option is (a) Client side objects

Easiest explanation: MEMORY leaks happen when your code needs to CONSUME memory in your APPLICATION, which should be released after a given TASK is completed but isn’t. Memory leaks occur when we are developing client-side reusable scripting objects.

The correct choice is (C) UNIQUE number is retrieved as elem[jQuery.expando] & Data is READ from jQuery.cache[id]

The EXPLANATION is: jQuery.cache[id] is used to associate handlers and other data with elements. When the data is read from an ELEMENT:

The element unique number is retrieved from id = elem[ jQuery.expando].

The data is read from jQuery.cache[id].

The CORRECT choice is (d) Geolocation API

To explain I would SAY: The Geolocation API allows the user to PROVIDE their location to web applications if they so DESIRE. For PRIVACY reasons, the user is asked for permission to report location information.