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JavaScript Objective Questions Set-2 (48)

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Question: 21

Example of arrays in Javascript. Find output of below code

<script>
var firstNames = ["c", "c++", "java", "python", "perl"];
for (var i = 0; i < firstNames.length; i++) {
if(i%2===0)
continue;
document.write(i);
}
</script>

(A) 012345
(B) 01234
(C) 135
(D) 13

Level: Practitioner Category: arrays

Question: 22

Can we create empty array in Javascript? Find the output of below code

<script>

var firstNames = []; //creating empty array

for (var i = 0; i <=firstNames.length; i++) {
document.write("Javascript");
}

</script>

(A) Error
(B) Nothing is printed
(C) Javascript
(D) JavascriptJavascript

Level: Practitioner Category: arrays

Question: 23

Math.ceil() and Math.floor() are methods which are used with number. How Javascript behaves when any character is passed instead of numbers? like 

<script>
var mathVal = Math.floor('f');
document.write(mathVal);
</script>

(A) It is Error
(B) Nothing is printed
(C) 0 is the output
(D) NaN is the output

Level: Expert Category: methods

Question: 24

What is the output of Math.ceil(0) in Javascript?

<script>
var mathVal = Math.ceil(0);
document.write(mathVal);
</script>

(A) 1
(B) 0
(C) NaN
(D) None of the above

Level: Expert Category: methods

Question: 25

Find the output of below code

<html>
<head>
<title>JavaScript Example</title>
 
<script type="text/javascript">
function getHeader() {
    return "<h1>Javascript Questions</h1>"
}
</script>

</head>
<body>
<script type="text/javascript">
    document.write(getHeader());
</script>

</body>
</html>

(A) <h1>Javascript Questions</h1>
(B) Javascript Questions
(C) Error
(D) "<h1>Javascript Questions</h1>"

Level: Practitioner Category: methods

Question: 26

Find the output of typecasting program in Java

<html>
<head>
<title>JavaScript Data Conversion Example</title>
<script>
document.write(parseFloat('77.3') + "#");
document.write(parseInt('77')+ "#");
document.write(parseInt('123.45')+ "#");
document.write(Number("2.34")+ "#");
</script>
</head>
<body>
</body>
</html>

(A) 77.300000#77#123#2.34#
(B) 77.300000#77#123#2#
(C) 77.300000#77#123#234#
(D) 77.3#77#123#2.34#

Level: Expert Category: methods

Question: 27

Find the output of below code

<script>
re=/[-]/;
target="254-96-9163";
result = target.split(re);
document.write(result[0] + result[1]);
</script>

(A) 350
(B) 25496
(C) 254-96
(D) Error

Level: Expert Category: regularexpressions

Question: 28

JavaScript is a case-sensitive language

(A) True
(B) False

Level: Beginner Category: variables

Question: 29

Find the output of below Javascript

<script>
re=/s/;
target="1 2 3 4 5";
result = target.split(re);
document.write(result.length + " & ");
var temp=0;
for(i=0;i<result.length;i++) {
temp+=parseInt(result[i]);
}
document.write(temp);
</script>
</script>

(A) 9 & 12345
(B) 9 & 5
(C) 9 & 15
(D) 5 & 15

Level: Expert Category: methods

Question: 30

Choose the method which Joins all elements of an array into a string

(A) join()
(B) concat()
(C) connect()
(D) add()

Level: Expert Category: methods

Question: 31

In JavaScript, Arrays are data type. State True or False

(A) True
(B) False

Level: Practitioner Category: arrays

Question: 32

In JavaScript, data stored in an array always have to be the same data type
State True or False

(A) True
(B) False

Level: Practitioner Category: arrays

Question: 33

Does JavaScript allow exception handling

(A) Yes, it provides try, catch as well as throw key word for exception handling
(B) Yes, but it provides only try block
(C) Yes, but it provides only Try catch block, but does not allow throw exception
(D) No

Level: Expert Category: exceptions

Question: 34

If an exception is thrown, the statements in the finally block execute even if no catch block handles the exception. State true or false

(A) True
(B) False

Level: Expert Category: exceptions

Question: 35

To create an image rollover which events need to be used

(A) OnMouseKeyDown
(B) OnMouseKeyUp
(C) onMouseout
(D) onMouseover

Level: Expert Category: methods

Question: 36

The event specific to keyboard is

(A) onkeyboardpress
(B) onkeydown
(C) onfocus
(D) onclick

Level: Practitioner Category: other

Question: 37

When the user is working with timing events in Javascript, select the event that would cancel the setTimeout()

(A) clearsetTimeout()
(B) stopTimeout()
(C) clearTimeout()
(D) cancelTimeout()

Level: Expert Category: methods

Question: 38

Which one of the following is not a popup box in JavaScript?

(A) Alert Box
(B) Prompt Box
(C) Confirm Box
(D) Message Box

Level: Expert Category: methods

Question: 39

Which of the following method checks if its argument is not a number?

(A) isNaN()
(B) nonNaN()
(C) NaN()
(D) None of the listed option

Level: Expert Category: methods

Question: 40

The shift method the first element of an array and returns the removed value. State true or false

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JavaScript Objective Questions Set-2 (48)

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