Explore topic-wise MCQs in Javascript.

This section includes 114 Mcqs, each offering curated multiple-choice questions to sharpen your Javascript knowledge and support exam preparation. Choose a topic below to get started.

101.

Which exception does the Iterators throw from their next() method when there are no more values to iterate, that work on finite collections ?

A. ExitIteration
B. AbortIteration
C. Abort
D. StopIteration
Answer» E.
Discussion
102.

Consider the following code snippetfunction oddsums(n) { let total = 0, result=[]; for(let x = 1; x <= n; x++) { let odd = 2*x-1; total += odd; result.push(total); } return result;}What would be the output ifoddsums(5);is executed afted the above code snippet ?

A. Returns [1,4,9,16,25]
B. Returns [1,2,3,4,5]
C. Returns [3,6,9,12,15]
D. Returns [1,3,5,7,9]
Answer» B. Returns [1,2,3,4,5]
Discussion
103.

Which was one of the first security subsets proposed?

A. FBJS
B. Caja
C. dojox.secure
D. ADSafe
Answer» E.
Discussion
104.

The keyword or the property that you use to refer to an object through which they were invoked is

A. from
B. to
C. this
D. object
Answer» D. object
Discussion
105.

What is the most essential purpose of parantheses in regular expressions ?

A. Define pattern matching techniques
B. Define subpatterns within the complete pattern
C. Define portion of strings in the regular expression
D. All of the mentioned
Answer» C. Define portion of strings in the regular expression
Discussion
106.

The four kinds of class members are

A. Instance methods, Instance fields, Static method, Dynamic method
B. Instance fields, Instance methods, Class fields, Class methods
C. Instance fields, Non-instance fields, Dynamic methods, Global methods
D. Global methods, Local methods, Dynamic methods, Static methods
Answer» C. Instance fields, Non-instance fields, Dynamic methods, Global methods
Discussion
107.

The provides() function and the exportsobject are used to

A. Register the module’s API and Store their API
B. Store the module’s API and register their API
C. Store the module’s API
D. None of the mentioned
Answer» B. Store the module‚Äö√Ñ√¥s API and register their API
Discussion
108.

Consider the following statement containing regular expressionsvar text = "testing: 1, 2, 3"; var pattern = /d+/g;In order to check if the pattern matches, the statement is

A. text==pattern
B. text.equals(pattern)
C. text.test(pattern)
D. pattern.test(text)
Answer» E.
Discussion
109.

Which is the correct code that returns a complex number that is the complex conjugate of this one?

A. Complex.prototype.conj = function() { return new Complex(this.r, -this.i); };
B. Complex.prototype.conj = function() { return Complex(this.r, -this.i); };
C. Complex.prototype.conj = function() { return (this.r, -this.i); };
D. Complex.prototype.conj = function() { new Complex(this.r, -this.i); };
Answer» B. Complex.prototype.conj = function() { return Complex(this.r, -this.i); };
Discussion
110.

The maximum number of global symbols a module can define is

A. 2
B. 3
C. 1
D. 4
Answer» D. 4
Discussion
111.

What is the code to be used to trim whitespaces ?

A. let trimmed = (l.trim() for (l in lines));
B. let trimmed = (trim(l));
C. let trimmed = l.trim();
D. let trimmed = for(l in lines));
Answer» B. let trimmed = (trim(l));
Discussion
112.

Which looping statement allows XML tags to appear in JavaScript programs and adds API for operating on XML data?

A. for loop
B. while loop
C. for/each loop
D. all of the mentioned
Answer» D. all of the mentioned
Discussion
113.

The main difference between the variables declared with var and with let is

A. var is confined to a particular function but let is not
B. let is confined to a particular function but var is not
C. var defines values based on conditions but let does not
D. none of the mentioned
Answer» C. var defines values based on conditions but let does not
Discussion
114.

The behaviour of the instances present of a class inside a method is defined by

A. Method
B. Classes
C. Interfaces
D. Classes and Interfaces
Answer» C. Interfaces
Discussion