Explore topic-wise InterviewSolutions in .

The correct answer is (c) Dead locks

To elaborate: APC supports four locking methods named File locks, Spin locks, Pthread mutex, IPC semaphores. File locks are the most STABLE, Spin LOCK gives the best performance, Pthread mutex is only available in Linux version 2.6, IPC semaphores are faster than file locks.

The correct answer is (a) STOPPING other sites from displaying images

The best I can explain: Hotlink protection is a kind of tool. Hotlink protection is related to RESTRICTING HTTP, it stops other sites from displaying images of your WEBPAGE. We can CREATE a list of hostnames that can access the resources of our website.

The correct CHOICE is (d) INVALID_STATE_ERR

Explanation: When SQLTRANSACTIONCALLBACK, SQLStatementErrorCallback, SQLStatementCallback does not execute then INVALID_STATE_ERR ERROR is RAISED. This error is raised from INSIDE a SQLTransactionErrorCallback.

The correct answer is (d) database name

Best EXPLANATION: transction() and readTransaction() are the TWO METHODS that take THREE arguments i.e. transaction callback as the first argument, error callback as the second argument, success callback as the third argument.

The correct ANSWER is (a)

Right answer is (b) Modernizr.hasEvent

To explain: If you want to create your own FEATURE DETECTS you can simply use Modernizr.addTest. Modernizr.hasEvent helps in determining browser support. It does detection of div element by default. Syntax is hasEvent(‘video’). But if we want to give an object to DETECT SOMETHING other than div, we can give second argument as hasEvent(‘blur’, WINDOW). It also returns a Boolean value. Modernizr.atRule is one of modernizr API(Application Programming Interface) having syntax like – Modernizr.atRule(prop). Modernizr.prefixed Modernizr API takes string CSS value in Document Object Model.

Correct answer is (a) web workers

Easy EXPLANATION: The support of basic web worker is DETECTED by web workers. Web workers mean running a script in the background for web content. Shared workers detect support of shared workers, data workers detect support for CREATING Web Workers from Data URI’s. BLOB workers detect support for creating web workers from Blob URI.

The correct OPTION is (b) any missing FILE

Explanation: HTTP 404 is an error which indicates that the client was able to communicate with the server but the server could not find the REQUEST. Due to missing of any file 404 error is generated, this is a taxing error for the PAGE.

The correct option is (a) CSS 2D TRANSFORMS

For explanation I WOULD say: Modernizr.csstransforms detects CSS 2D transforms introduced by HTML5. CSS 3D transform is DETECTED by Modernizr.csstransforms3d. INPUT types are detected by Modernizr.inputtypes[type], Input Attributes is detected by Modernizr.input[attribute].

Correct answer is (c) Modernizr.testStyles

Explanation: Modernizr.testProp is just like Modernizr.testAllProps but only difference is it doesn’t check for vendor. The features that can’t be check by IDL is checked by Modernizr.testStyles, it takes CSS RULE and embed it ONTO current page with DOM elements. SYNTAX is

Correct choice is (d) DNS

Explanation: A identity indicates no compression. Compress is a method that uses UNIX compress, it is based on LZW ALGORITHM. Gzip is the most famous compression FORMAT, deflate is a kind of gzip WITHOUT checksum header, it is little faster but LESS efficient. DNS stands for Domain Name SYSTEM and is a naming system in computers.

Right ANSWER is (d) Atomic Layer

Easiest explanation: OSI model stands for Open Systems Interconnection model. It is commonly used for representing various parts of network TRAFFIC. There are SEVEN layers in the OSI model, Physical Layer, Data LINK layer, Network Layer, Transport Layer, Session Layer, Presentation Layer and Application Layer.

The CORRECT choice is (a) read-only

The BEST I can EXPLAIN: The .content property is a read-only property i.e a DocumentFragment which CONTAINS GUTS of template.

Right choice is (d) Pixelomator

For EXPLANATION: There are many SPRITE SHEET generators such as Lemonade, Compass, SpriteMe, Fireworks CS6. Lemonade, Compass, and SpriteMe are AVAILABLE free of COST but Fireworks CS6 is not free of cost. Pixelomator is image editing software.

The correct choice is (b) Network ENTRY

Explanation: There are four types of resources in an APPLICATION cache which are 1) Master Entries 2) EXPLICIT Entries 3) Network Entries 4) Fallback Entries. Resources are EXPLICITLY listed in the application’s cache manifest FILE by the explicit entry. Fallback entry provides fallback entries in the application’s manifest file. Master entries are the resources added to the cache. Network entry executes and load scripts and code from the server, not from the cache. Syntax is

CACHE MANIFEST

NETWORK:

/api

Resources are explicitly listed in a cache in explicit entries. When attempt to load fails fallback entry is used.

Right CHOICE is (c) Version 10.0

Explanation: Web workers are BACKGROUND threads running separate scripts. All the latest BROWSERS support web workers. Version 3.5 of web workers is introduced in FIREFOX, version 10.0 in Internet Explorer, version 10.6 in Opera, version 4.0 in Chrome, version 4.0 in Safari.

The correct ANSWER is (a) Netscape 4.60+

For explanation: GZIP or deflate is partially supported by Netscape 4.60+. Netscape 6+, IE 4+, Opera 5+, Safari, Chrome, Lynx 2.6+ and Firefox FULLY support Gzip compression, IE 4.5 and 5 does not support Gzip compression, IE 5.5 and 6.0, IE 6.0 SPI, IE 6,7,8 partially support Gzip compression.

The correct choice is (d) server name

Easiest explanation: OPENDATABASE() and openDatabaseSync() METHODS takes the name of the database, version of the database, display name, ESTIMATED size in bytes of the DATA that is to be stored in the database. openDtabase() method WORKS on WorkerUtils and Window, openDatabaseSync() method works on WorkerUtils.

The correct CHOICE is (b) 300 MB

The explanation: Maximum Cache size for Chrome is 300 MB, for Safari it is UNLIMITED, For Opera 10+ it is 400 MB, for Firefox 17 the maximum cache size is 1024 MB, for Internet EXPLORER 6,7,8 it is 50 MB and for Internet Explorer maximum cache size is 250 MB.

Right choice is (b) BOTTOM of the code

The best I can explain: For BETTER loading time of the page it is always recommended to put JAVASCRIPT code at the bottom of the MAIN code of the page before

tag. CSS code should be at the beginning of the code.

The CORRECT choice is (a) client and host

The BEST explanation: HTTP stands for Hypertext Transfer Protocol. For fetching, data from SERVER browser uses HTTP request, and in between client and host. The more HTTP request slower the LOADING of a page will be.

Right answer is (a) SpriteMe

To explain: SpriteMe is brilliant sprite SHEET VIEWER and generator. It is available at a free of cost. We can DESIGN our website USING individual images. It is very simple to use. By using SpriteMe we can ALSO view current sprite sheets that are already present on a website.

Right CHOICE is (a) _

The best EXPLANATION: There are two TYPE of characters RESERVED and unreserved characters. Characters that are allowed in URL but not have any reserved PURPOSE are unreserved characters. These are the characters from A-Z, a-z, 0-9, ‘~’, ‘_’, ‘.’, ‘-‘.

Correct OPTION is (B) >

The best I can EXPLAIN: Reserved CHARACTERS are ‘@’, ‘=’, ‘?’, ‘:’, ‘;’, ‘/’, ‘,’, ‘+’, ‘$’, ‘&’. Unsafe characters are space, ‘”’, ‘>’, ‘<’, ‘#’, ‘%’, ‘{‘, ‘}’, ‘~’, ‘^’, ‘[‘, ‘|’, ‘\’, ‘`’, ‘]’. There is a URL Encode for all of these characters. Apart from URL Encode there is Decimal and Hex VALUE also for the characters.

The correct choice is (b) 1

Best explanation: Multi-Process Modules i.e. MPMs is introduced by APACHE 2, it CONTROLS how Apache handles the requests. We can load only ONE MPM at a time. But in the case of Linux, we can USE two MPMs. There are two kind of MPM, worker and prefork.

Correct option is (a) read_buffer_size

For explanation I would say: For PERFORMING SEQUENTIAL SCANS of tables we USED read_buffer_size, when reading sorted rows we use read_rnd_buffer_size, join_buffer_size are allocated per-session thus for multiple join buffers MAY be created. For performing sort operation we use sort_buffer_size.

Right ANSWER is (b) 2-D IMAGES

For explanation I would say: 2-D images are sprites. Sprite is a big image which is made up of combining small images into one larger image. It is DEFINED by X and Y COORDINATES. CSS background-POSITION property is used to define the exact position that is to be displayed.

Right OPTION is (d) ?

The explanation is: ‘?’ is used for the placeholder. Binding of the ? placeholder is done at a literal level. It is DYNAMICALLY INSERTED into the statement. ‘?’ can be used in place of literals in SQL statements. If this CHARACTER is not supported then the error code 5 is invoked.

Correct choice is (d) cache status

The explanation is: If the files are not in cache they COME from a list of the files in the network. Cache is the default SECTION. The files those are LISTED under this header are explicitly cached after downloading for the first TIME. If the RESOURCE is inaccessible then this section will be in use. There is no any rule to list these section, can be listed in any order.

The correct option is (c) at the top of the CODE

To explain I would say: CSS STYLING and code should be placed at the top of the code for BEST loading result of the webpage. JavaScript code should be placed at the BOTTOM of the page for best performance and rapid loading speed of the website.

The correct CHOICE is (c) Live.js

To explain: There are templating libraries like Handlebars, MUSTACHE, Underscore JS library. Handlebars are like regular HTML which is embedded with handlebars expressions, Mustache is used with JAVASCRIPT, Underscore JS library is ONE of the JavaScript libraries which PROVIDES various useful functional programming.

Right OPTION is (d) Splashup

Explanation: Web PROFESSIONALS use VARIOUS tools for image OPTIMIZATION. Adobe Photoshop, Pixelmator, PaintShop Pro, Paint.net, Adobe Fireworks are some of them. There are online EDITORS also like photoshop.com, splashup.com, pixler.com, ipiccy.com, photoshop.com.

The correct option is (a) Modernizr._prefixes

Best explanation: Modernizr._prefixes is internal list of prefixes. It is SET against THINGS LIKE prefixedCSS and prefixed. It is an array of kebab-case VENDOR.

The correct answer is (B) SQLTransactionSync

To elaborate: For read-only transaction, we create the object SQLTransactionSync. If the first argument is NULL then we throw SQLEXCEPTION which is ERROR code 0. SQLTransactionSync object is FRESH initially but when it is marked as stale it is committed or ROLLED back.

The correct ANSWER is (b) WEBP Lossless

The BEST I can explain: Webp Lossless detects for lossless webp, non-alpha webp support. Webp TESTS for all forms of webp support like alpha, lossy, animated, lossless etc. Webp Animation detects for the support of animation in webp, Webp Alpha detects the support of TRANSPARENT webp.

Right CHOICE is (a) there are so many colors in the picture

The explanation: When we have different colors in a picture we use JPEG format. But when images have few colors or have large AREAS of the same color we use PNG or GIF format. Photographs that CONTAIN sky, snow, grass etc. are not suitable for PNG or GIF format.

Correct option is (d)

The correct option is (b) Optimus wordpress plugin

To explain: Optimus WordPress plugin is used for LOSSLESS as well as LOSSY image compression. It automatically reduces the size of the file. Reduction in size is possible up to 70%. There are three versions of Optimus i.e. Optimus HQ, Optimus, Optimus HQ PRO. Speed test TOOLS are used to measure/note down your PAGES speed performance. WordPress cache enable a plugin used to enable caching.

Right option is (d) delete database

The EXPLANATION is: We store VARIOUS information in the database. A database is a collection of tables that contain information. Database DELAY TAKES a long waiting TIME, so there are various techniques for database optimization. Database optimization basically optimizes data types, tables, data size.

Right choice is (d) Sizes

To explain: Sizes test for the sizes attribute for images. IMAGE crossOrigin is used to check the support of crossOrigin attribute on images, it allows CROSS domain images on a CANVAS, JPEG 2000 and JPEG XR are respectively for the check of JPEG 2000 and JPEG XR FORMATS on the images.