![MCQs [2024]](https://engineeringinterviewquestions.com/wp-content/uploads/2021/02/Interview-Questions-2.png)
JavaScript Online Test and Answers Pdf Download :-
These are very useful & Most Asked Questions in your certification Exam. Read all Online Mock Test Exam Question Bank for Beginners Freshers & Experienced.
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
Answer: B
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
Answer: A
3. ______ JavaScript is also called client-side JavaScript.
A. Microsoft
B. Navigator
C. LiveWire
D. Native
Answer: B
4. __________ JavaScript is also called server-side JavaScript.
A. Microsoft
B. Navigator
C. LiveWire
D. Native
Answer: C
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
Answer: A
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
Answer: A
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
Answer: A
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
Answer: C
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
Answer: C
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
Answer: A
11. ______ tag is an extension to HTML that can enclose any number of JavaScript statements.
A. <SCRIPT>
B. <BODY>
C. <HEAD>
D. <TITLE>
Answer: A
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
Answer: A
13. Which of the following attribute can hold the JavaScript version?
A. LANGUAGE
B. SCRIPT
C. VERSION
D. None of the above
Answer: A
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”)
Answer: C
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>
Answer: C
16. Inside which HTML element do we put the JavaScript?
A. <js>
B. <scripting>
C. <script>
D. <javascript>
Answer: C
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
Answer: C
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
Answer: B
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
Answer: A
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”
Answer: C
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
Answer: A
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”;
Answer: B
23. JavaScript entities start with _______ and end with _________.
A. Semicolon, colon
B. Semicolon, Ampersand
C. Ampersand, colon
D. Ampersand, semicolon
Answer: D
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.
Answer: D
25. Choose the server-side JavaScript object?
A. FileUpLoad
B. Function
C. File
D. Date
Answer: C
26. Choose the client-side JavaScript object?
A. Database
B. Cursor
C. Client
D. FileUpLoad
Answer: D
27. Which of the following is not considered a JavaScript operator?
A. new
B. this
C. delete
D. typeof
Answer: B
28. ______method evaluates a string of JavaScript code in the context of the specified object.
A. Eval
B. ParseInt
C. ParseFloat
D. Efloat
Answer: A
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
Answer: B
30. The syntax of Eval is ________________
A. [objectName.]eval(numeriC.
B. [objectName.]eval(string)
C. [EvalName.]eval(string)
D. [EvalName.]eval(numeriC.
Answer: B
JAVASCRIPT Objective Type Questions with Answers
31. JavaScript is interpreted by _________
A. Client
B. Server
C. Object
D. None of the above
Answer: A
32. Using _______ statement is how you test for a specific condition.
A. Select
B. If
C. Switch
D. For
Answer: B
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}
Answer: C
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])
Answer: A
35. The _______ method of an Array object adds and/or removes elements from an array.
A. Reverse
B. Shift
C. Slice
D. Splice
Answer: D
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 );
Answer: A
37. Which tag(s) can handle mouse events in Netscape?
A. <IMG>
B. <A>
C. <BR>
D. None of the above
Answer: B
38. ____________ is the tainted property of a window object.
A. Pathname
B. Protocol
C. Defaultstatus
D. Host
Answer: C
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
Answer: C
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
Answer: A
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
Answer: B
42. _______ class provides an interface for invoking JavaScript methods and examining JavaScript properties.
A. ScriptObject
B. JSObject
C. JavaObject
D. Jobject
Answer: B
43. _________ is a wrapped Java array, accessed from within JavaScript code.
A. JavaArray
B. JavaClass
C. JavaObject
D. JavaPackage
Answer: A
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
Answer: B
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
Answer: B
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);
Answer: D
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);
Answer: A
48. The syntax of a blur method in a button object is ______________
A. Blur()
B. Blur(contrast)
C. Blur(value)
D. Blur(depth)
Answer: A
49. The syntax of capture events method for document object is ______________
A. captureEvents()
B. captureEvents(args eventType)
C. captureEvents(eventType)
D. captureEvents(eventVal)
Answer: C
50. The syntax of close method for document object is ______________
A. Close(do).
B. Close(object)
C. Close(val)
D. Close()
Answer: D
51. <script type=”text/javascript”>
x=4+”4″;
document.write(x);
</script>
Output——?
A. 44
B. 8
C. 4
D. Error output
Answer: A
52. Is it possible to nest functions in JavaScript?
A. True
B. False
Answer: A
53. <script>
document.write(navigator.appCodeName);
</script>
A. get code name of the browser of a visitor
B. set code name of the browser of a visitor
C. None of the above
Answer: A
54. Scripting language are
A. High Level Programming language
B. Assembly Level programming language
C. Machine level programming language
Answer: A
55. Which best explains getSelection()?
A. Returns the VALUE of a selected OPTION.
B. Returns document.URL of the window in focus.
C. Returns the value of cursor-selected text
D. Returns the VALUE of a checked radio input.
Answer: C
56. Choose the client-side JavaScript object:
A. Database
B. Cursor
C. Client
D. FileUpLoad
Answer: D
57. What is mean by “this” keyword in javascript?
A. It refers current object
B. It referes previous object
C. It is variable which contains value
D. None of the above
Answer: A
58. In JavaScript, Window.prompt() method return true or false value ?
A. False
B. True
Answer: A
59. <script language=”javascript”>
function x()
{
document.write(2+5+”8″);
}
</script>
A. 258
B. Error
C. 7
D. 78
Answer: D
60. <script type=”text/javascript”>
var s = “9123456 or 80000?”;
var pattern = /d{4}/;
var output = s.match(pattern);
document.write(output);
</script>
A. 9123
B. 91234
C. 80000
D. None of the above
Answer: A