JavaScript MCQs (Chapterwise Multiple Choice Questions)

what is the type of i? var i = NaN;

NaN

number

null

undefined

Answer & Explanation

Correct Answer: number

Note: This Question is unanswered, help us to find answer for this one

What will be the output of the following code: for (var i = 0; i < 5; i++) { (function(x) { setTimeout(function() { console.log(x); }, x * 1000 ); })(i); }

1 2 3 4 5

0 1 2 3 4

5 5 5 5 5

Answer & Explanation

Correct Answer: 0 1 2 3 4

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What will the value of y be in this code: const x = 6 % 2; const y = x ? 'One' : 'Two';

One

Undefined

TRUE

Two

Answer & Explanation

Correct Answer: Two

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What is the RegExp object constructor used for?

Provides access to Windows registry express values

Regulates the expression of variables

Match text against regular expressions

Switches numerical notation to exponential

Registers experienced functions with the DOM

Answer & Explanation

Correct Answer: Match text against regular expressions

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What is the result of the following expression? ({"foo": true}).foo;

false

undefined

true

4

SyntaxError

Answer & Explanation

Correct Answer: true

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Consider the following code: var bar = (function(){ function Bar(){}; return new Bar(); })(); How will you make another instance of Bar?

new bar()

new bar

Object.create(bar)

new bar.constructor()

Answer & Explanation

Correct Answer: new bar.constructor()

Note: This Question is unanswered, help us to find answer for this one

Which statement is True for Behavioral design patterns?

Behavioral design patterns are all about the composition of objects and relationships among them

Behavioral design patterns focus on the interdependency and communication between objects

Behavioral design patterns deal with various mechanisms of object creation

Behavioral design patterns patterns look at optimized or more controlled mechanisms of object creation

Answer & Explanation

Correct Answer: Behavioral design patterns focus on the interdependency and communication between objects

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How do you construct a RegExp object?

var re = new RegExp('ab+c', 'i');

var re = RegExp('ab+c', 'i');

var re; re.RegExp('ab+c', 'i');

var re = new RegExp(/ab+c/i);

Answer & Explanation

Correct Answer: var re = new RegExp('ab+c', 'i');

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Which symbol is not used in logical operations?

||

&&

%

!

Answer & Explanation

Correct Answer: %

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An infinite loop is an example of a(n) ____ error.

Synta x

Run- time

Logic

User

Answer & Explanation

Correct Answer: Logic

Note: This Question is unanswered, help us to find answer for this one

JavaScript Quick Quiz

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