50 JavaScript & AJAX interview questions

1.  Why so JavaScript and Java have similar name?

A.  JavaScript is a stripped-down version of Java

B.  JavaScript's syntax is loosely based on Java's

C.  They both originated on the island of Java

D.  None of the above

 

2.  When a user views a page containing a JavaScript program, which machine actually executes the script?

A.  The User's machine running a Web browser

B.   The Web server

C.  A central machine deep within Netscape's corporate offices

D.  None of the above

 

3.  ______ JavaScript is also called client-side JavaScript.

A.  Microsoft

B.  Navigator

C.  LiveWire

D.  Native

 

4.  __________ JavaScript is also called server-side JavaScript.

A.  Microsoft

B.   Navigator

C.  LiveWire

D.  Native

 

5.  What are variables used for in JavaScript Programs?

A.  Storing numbers, dates, or other values

B.   Varying randomly

C.  Causing high-school algebra flashbacks

D.  None of the above

 

6.  _____ JavaScript statements embedded in an HTML page can respond to user events such as mouse-clicks, form input, and page navigation.

A.  Client-side

B.   Server-side

C.  Local

D.  Native

 

7.  What should appear at the very end of your JavaScript?

The <script LANGUAGE="JavaScript">tag

A.   The </script>

B.    The <script>

C.  The END statement

D.  None of the above

 


8.  Which of the following can't be done with client-side JavaScript?

A.  Validating a form

B.   Sending a form's contents by email

C.  Storing the form's contents to a database file on the server

D.  None of the above

 

9.  Which of the following are capabilities of functions in JavaScript?

A.  Return a value

B.   Accept parameters and Return a value

C.  Accept parameters

D.  None of the above

 

10.  Which of the following is not a valid JavaScript variable name?

A.  2names

B.   _first_and_last_names

C.  FirstAndLast

D.  None of the above

 

11.  ______ tag is an extension to HTML that can enclose any number of JavaScript statements.

A.  <SCRIPT>

B.   <BODY>

C.  <HEAD>

D.  <TITLE>

 

12.  How does JavaScript store dates in a date object?

A.  The number of milliseconds since January 1st, 1970

B.   The number of days since January 1st, 1900

C.  The number of seconds since Netscape's public stock offering.

D.  None of the above

 

13.  Which of the following attribute can hold the JavaScript version?

A.  LANGUAGE

B.   SCRIPT

C.  VERSION

D.  None of the above

 

14.  What is the correct JavaScript syntax to write "Hello World"?

A.  System.out.println("Hello World")

B.   println ("Hello World")

C.  document.write("Hello World")

D.  response.write("Hello World")

 

15.  Which of the following way can be used to indicate the LANGUAGE attribute?

A.  <LANGUAGE="JavaScriptVersion">

B.   <SCRIPT LANGUAGE="JavaScriptVersion">

C.  <SCRIPT LANGUAGE="JavaScriptVersion">    JavaScript statements…</SCRIPT>

D.  <SCRIPT LANGUAGE="JavaScriptVersion"!>    JavaScript statements…</SCRIPT>

 

16.  Inside which HTML element do we put the JavaScript?

A.  <js>

B.   <scripting>

C.  <script>

D.  <javascript>

 

17.  What is the correct syntax for referring to an external script called " abc.js"?

A.  <script href=" abc.js">

B.   <script name=" abc.js">

C.  <script src=" abc.js">

D.  None of the above

 

18.  Which types of image maps can be used with JavaScript?

A.  Server-side image maps

B.  Client-side image maps

C.  Server-side image maps and Client-side image maps

D.  None of the above

 

19.  Which of the following navigator object properties is the same in both   Netscape and IE?

A.  navigator.appCodeName

B.   navigator.appName

C.  navigator.appVersion

D.  None of the above

 

20.  Which is the correct way to write a JavaScript array?

A.  var txt = new Array(1:"tim",2:"kim",3:"jim")

B.   var txt = new Array:1=("tim")2=("kim")3=("jim")

C.  var txt = new Array("tim","kim","jim")

D.  var txt = new Array="tim","kim","jim"

 

21.  What does the <noscript> tag do?

A.  Enclose text to be displayed by non-JavaScript browsers.

B.   Prevents scripts on the page from executing.

C.  Describes certain low-budget movies.

D.  None of the above

 

22. If para1 is the DOM object for a paragraph, what is the correct syntax to change the text within the paragraph?

A.  "New Text"?

B.  para1.value="New Text";

C.  para1.firstChild.nodeValue= "New Text";

D.  para1.nodeValue="New Text";

 

23.  JavaScript entities start with _______ and end with _________.

A.  Semicolon, colon

B.   Semicolon, Ampersand

C.  Ampersand, colon

D.  Ampersand, semicolon

 

24.  Which of the following best describes JavaScript?

A.  a low-level programming language.

B.   a scripting language precompiled in the browser.

C.  a compiled scripting language.

D.  an object-oriented scripting language.

 

25.  Choose the server-side JavaScript object?

A.  FileUpLoad

B.   Function

C.  File

D.  Date

 

26.  Choose the client-side JavaScript object?

A.  Database

B.   Cursor

C.  Client

D.  FileUpLoad

 

27.  Which of the following is not considered a JavaScript operator?

A.  new

B.  this

C.  delete

D.  typeof

 

28.  ______method evaluates a string of JavaScript code in the context of the specified object.

A.  Eval

B.   ParseInt

C.  ParseFloat

D.  Efloat

 

29.  Which of the following event fires when the form element loses the focus: <button>, <input>, <label>, <select>, <textarea>?

A.  onfocus

B.  onblur

C.  onclick

D.  ondblclick

 

30.  The syntax of Eval is ________________

A.  [objectName.]eval(numeric)

B.  [objectName.]eval(string)

C.  [EvalName.]eval(string)

D.  [EvalName.]eval(numeric)

 

31.  JavaScript is interpreted by _________

A.  Client

B.   Server

C.  Object

D.  None of the above

 

32.  Using _______ statement is how you test for a specific condition.

A.  Select

B.  If

C.  Switch

D.  For

 

33.  Which of the following is the structure of an if statement?

A.  if (conditional expression is true) thenexecute this codeend if

B.   if (conditional expression is true)execute this codeend if

C.  if (conditional expression is true)   {then execute this code>->}

D.  if (conditional expression is true) then {execute this code}

 

34.  How to create a Date object in JavaScript?

A.  dateObjectName = new Date([parameters])

B.   dateObjectName.new Date([parameters])

C.  dateObjectName := new Date([parameters])

D.  dateObjectName Date([parameters])

 

35.  The _______ method of an Array object adds and/or removes elements from an array.

A.  Reverse

B.   Shift

C.  Slice

D.  Splice

 

36.  To set up the window to capture all Click events, we use which of the following statement?

A.  window.captureEvents(Event.CLICK);

B.   window.handleEvents (Event.CLICK);

C.  window.routeEvents(Event.CLICK );

D.  window.raiseEvents(Event.CLICK );

 

37.  Which tag(s) can handle mouse events in Netscape?

A.  <IMG>

B.  <A>

C.  <BR>

D.  None of the above

 

38.  ____________ is the tainted property of a window object.

A.  Pathname

B.   Protocol

C.  Defaultstatus

D.  Host

 

39.  To enable data tainting, the end user sets the _________ environment variable.

A.  ENABLE_TAINT

B.   MS_ENABLE_TAINT

C.  NS_ENABLE_TAINT

D.  ENABLE_TAINT_NS

 

40.  In JavaScript, _________ is an object of the target language data type that encloses an object of the source language.

A.  a wrapper

B.   a link

C.  a cursor

D.  a form

 

 

 

41.  When a JavaScript object is sent to Java, the runtime engine creates a Java wrapper of type ___________

A.  ScriptObject

B.  JSObject

C.  JavaObject

D.  Jobject

 

42.  _______ class provides an interface for invoking JavaScript methods and examining JavaScript properties.

A.  ScriptObject

B.  JSObject

C.  JavaObject

D.  Jobject

 

43.  _________ is a wrapped Java array, accessed from within JavaScript code.

A.  JavaArray

B.   JavaClass

C.  JavaObject

D.  JavaPackage

               

44. A ________ object is a reference to one of the classes in a Java package, such as netscape.javascript .

A.  JavaArray

B.  JavaClass

C.  JavaObject

D.  JavaPackage

 

45.  The JavaScript exception is available to the Java code as an instance of __________

A.  netscape.javascript.JSObject

B.  netscape.javascript.JSException

C.  netscape.plugin.JSException

D.  None of the above

 

46. To automatically open the console when a JavaScript error occurs which of the following is added to prefs.js?

A.  user_pref(" javascript.console.open_on_error", false);

B.   user_pref("javascript.console.open_error ", true);

C.  user_pref("javascript.console.open_error ", false);

D.   user_pref("javascript.console.open_on_error", true);

 

47.  To open a dialog box each time an error occurs, which of the following is added to prefs.js?

A.  user_pref("javascript.classic.error_alerts", true);

B.   user_pref("javascript.classic.error_alerts ", false);

C.  user_pref("javascript.console.open_on_error ", true);

D.  user_pref("javascript.console.open_on_error ", false);

 

48.  The syntax of a blur method in a button object is ______________

A.  Blur()

B.   Blur(contrast)

C.  Blur(value)

D.  Blur(depth)

 

49.  The syntax of capture events method for document object is ______________

A.  captureEvents()

B.   captureEvents(args eventType)

C.  captureEvents(eventType)

D.  captureEvents(eventVal)

 

50.  The syntax of close method for document object is ______________

A.  Close(doc)

B.   Close(object)

C.  Close(val)

D.  Close()

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One Comment on 50 JavaScript & AJAX interview questions

  1. James
    Posted 9/30/2008 at 12:44 am | Permalink

    This is what I found to be inaccurate with this, which is sad. Any errors in this post are due to my misunderstanding of javascript ( I do not believe I’ve made any mistakes ). I apologize upfront for any errors.

    9: All of them except D is a correct answer as a function can return a value, accept variables and then return a value or just accept values.

    32: Switch can also be used to test for conditions.

    48: Question also has no correct answer as blur() cannot be capitalized.

    50: Same as 48, capitalization of a method will invalidate that methods use. Close() != close().

    I’m sure others with a more thorough understanding can find other errors ( or point ones out that I may have made ).

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