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SSC Stenographer - JavaScript 1000+ MCQ [Solved] PDF Download

Thursday 9th of March 2023

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1. What will be the output of the following JavaScript code?
var a1 = [,,,];
var a2 = new Array(3);
0 in a1
0 in a2

A. true false
B. false true
C. true true
D. false true
Answer : A
2. What will be the output of the following JavaScript code?
var values=[1,2,3,4]
var ans=values.slice(1);
document.writeln(ans);

A. 1, 2, 3, 4
B. 2, 3, 4
C. 1, 3, 4
D. error
Answer : D
3. What will be the output of the following Javascript code?
var txt1 = good;
var txt2 = day;
document.getElementById(demo).innerHTML = txt1 + txt2;

 


A. good day
B. goodday
C. error
D. undefined
Answer : B
4. What will be the output of the following JavaScript code?
int sum=0;
var arr = [10,15,20,30];
arr.forEach(function myFunction(element)
{
sum= sum+element;
});
document.writeln(sum);

A. 70
B. 75
C. 10
D. error
Answer : B
5. The enumeration order becomes implementation dependent and non-interoperable if ___________
A. If the object inherits enumerable properties
B. The object does not have the properties present in the integer array indices
C. The delete keyword is never used
D. Object.defineProperty() is not used
Answer : A
6. What will happen if the body of a for/in loop deletes a property that has not yet been enumerated?
A. The property will be stored in a cache
B. The loop will not run
C. That property will not be enumerated
D. The property will be enumerated
Answer : C
7. What are the three important manipulations done in a for loop on a loop variable?
A. Updation, Incrementation, Initialization
B. Initialization,Testing, Updation
C. Testing, Updation, Testing
D. Initialization,Testing, Incrementation
Answer : B
8. What will be the output of the following JavaScript code?
var grade='A';
var result;
switch(grade)
{
case 'A':
result+=10;
case 'B':
result+= 9;
case 'C':
result+= 8;
default:
result+= 0;
}
document.write(result);

A. 10
B. 27
C. 8
D. 0
Answer : B
9. To determine whether one object is the prototype of (or is part of the prototype chain of) another object, one should use the ____________
A. isPrototypeOf() method
B. equals() method
C. === operator
D. ==opertor
Answer : A
10. Which keyword is used to define the function in javascript?
A. void
B. int
C. function
D. main
Answer : C
11. The var and function are __________
A. Keywords
B. Declaration statements
C. Data types
D. Prototypes
Answer : B
12. What will be the output of the following JavaScript code?

A. 1.01
B. 1.047
C. 1.00
D. 1.4
Answer : B
13. The expression of calling (or executing) a function or method in JavaScript is called ________
A. Primary expression
B. Functional expression
C. Invocation expression
D. Property Access Expression
Answer : C
14. What is the observation made in the following JavaScript code?
var count = [1,,3];

A. The omitted value takes undefined
B. This results in an error
C. This results in an exception
D. The omitted value takes an integer value
Answer : A
15. What will be the output of the following Javascript code?
<script>
txt1 = “ one”;
txt1 += “two”;
document.getElementById("demo").innerHTML = txt1;
</script>



A. onetwo
B. one two
C. error
D. undefined
Answer : A
16. Consider the following code snippet.
function printArray(a)
{
var len = a.length, i = 0;
if (len == 0)
console.log(Empty Array);
else
{
do
{
console.log(a[i]);
} while (++i < len);
}
}

What does the above code result?

A. Prints the numbers in the array in order
B. Prints the numbers in the array in the reverse order
C. Prints 0 to the length of the array
D. Prints Empty Array
Answer : A
17. Do functions in JavaScript necessarily return a value?
A. It is mandatory
B. Not necessary
C. Few functions return values by default
D. some functions do not return any value
Answr : C
18. Which attribute is used to specify that the script is executed when the page has finished parsing? (only for external scripts)
A. parse
B. a sync
C. defer
D. type
Answer : C
19. What will be the output of the following JavaScript code?
var values=[one,two,Three];
var ans=values.shift();
document.writeln(ans);

A. one
B. two
C. three
D. error
Answer : A
20. A proper scripting language is a __________
A. High level programming language
B. Assembly level programming language
C. Machine level programming language
D. Low level programming language
Answer : A
21. What will be the output of the following Javascript code?
function range(int length)
{
int a=5;
for(int i=0;i<length;i++)
{
console.log(a);
}
}
range(3);

A. 5
B. 555
C. 3
D. error
Answer : B
22. What will be the output of the following JavaScript code?
const obj = {prop: 12};
Object.preventExtensions(obj);
console.log( Object.isExtensible(obj));

A. 12
B. false
C. true
D. error
Answer : B
23. What will the following code snippet work? If not, what will be the error?
function tail(o)
{
for (; o.next; o = o.next) ;
return o;
}

A. No, this will throw an exception as only numerics can be used in a for loop
B. No, this will not iterate
C. Yes, this will work
D. No, this will result in a runtime error with the message Cannot use Linked List
Answer : C
24. What will be the output of the following JavaScript code?
Int a=1;
if(a>10)
{
document.write(10);
}
else
{
document.write(a);
}

A. 10
B. 0
C. 1
D. Undefined
Answer : C
25. Identify the process done in the following JavaScript code snippet?
o = {x:1, y:{z:[false,null,]}};
s = JSON.stringify(o);
p = JSON.parse(s);

A. Object Encapsulation
B. Object Serialization
C. Object Abstraction
D. Object Encoding
Answer : B
26. Among the keywords below, which one is not a statement?
A. debugger
B. with
C. if
D. use strict
Answer : D
27. What will be the output of the following Javascript code?
<script>
var x = 10;
x *= 5;
document.getElementById("demo").innerHTML = x;
</script>



A. 5
B. 10
C. 50
D. Error
Answer : C
28. Consider the following JavaScript statements.
var text = testing: 1, 2, 3; // Sample text
var pattern = /d+/g // Matches all instances of one or more digits

In order to check if the pattern matches with the string text, the statement is ____________

A. text==pattern
B. text.equals(pattern)
C. text.test(pattern)
D. pattern.test(text)
Answer : D
29. The method or operator used to identify the array is __________
A. isarrayType()
B. ==
C. ===
D. typeof
Answer : D
30. What will be the output of the following JavaScript code?
var grade='B';
var result;
switch(grade)
{
case 'A':
{
result+=10;
break;
}
case 'B':
{
result+= 9;
break;
}
case 'C':
{
result+= 8;
break;
}
default:
result+= 0;
}
document.write(result);

A. 10
B. 9
C. 8
D. 0
Answer : B
31. What is the observation made in the following JavaScript code?
if (!a[i]) continue;

A. Skips the defined elements
B. Skips the existent elements
C. Skips the null elements
D. Skips the defined & existent elements
Answer : C
32. What will be the output of the following JavaScript code?
var grade='E';
var result;
switch(grade)
{
case 'A':
result+=10;
case 'B':
result+= 9;
case 'C':
result+= 8;
default:
result+= 0;
}
document.write(result);

A. 10
B. 0
C. 18
D. 17
Answer : B
33. Which of the following Attribute is used to include External JS code inside your HTML Document?
A. src
B. ext
C. script
D. link
Answer : A
34. What will be the output of the following JavaScript code?
const object1 = {
property1: 20
};
console.log(Object.is(object1));

A. 20
B. true
C. false
D. error
Answer : C
35. Consider the following code snippet :
var c = counter(), d = counter();
c.count()
d.count()
c.reset()
c.count()
d.count()

The state stored in d is :

A. 1
B. 0
C. Null
D. Undefined
Answer : A
36. The escape sequence stands for _________
A. Floating numbers
B. Representation of functions that returns a value
C. is not present in JavaScript
D. Form feed
Answer : D
37. What will be the output of the following JavaScript code?
function printprops(o)
{
for(var p in o)
console.log(p + : + o[p] +
);
}

A. Prints the contents of each property of o
B. Returns undefined
C. Prints only one property
D. Prints the address of elements
Answer : B
38. What will be the output of the following JavaScript code?

A. 7.25
B. -7.25
C. 7
D. -7
Answer : A
39. The snippet that has to be used to check if a is not equal to null is _________
A. if(a!=null)
B. if (!a)
C. if(a!null)
D. if(a!==null)
Answer : D
40. What is the difference between the two lines given below ?
!!(obj1 && obj2);
(obj1 && obj2);

A. Both the lines result in a boolean value True
B. Both the lines result in a boolean value False
C. Both the lines checks just for the existence of the object alone
D. The first line results in a real boolean value whereas the second line merely checks for the existence of the objects
Answer : D
41. A JavaScript program developed on a Unix Machine ________
A. will throw errors and exceptions
B. must be restricted to a Unix Machine only
C. will work perfectly well on a Windows Machine
D. will be displayed as a JavaScript text on the browser
Answer : C
42. Consider the following code snippet :
function constfuncs()
{
var funcs = [];
for(var i = 0; i < 10; i++)
funcs[i] = function() { return i; };
return funcs;
}
var funcs = constfuncs();
funcs[5]()

What does the last statement return ?

A. 9
B. 0
C. 10
D. None of the mentioned
Answer : C
43. What will be the output of the following JavaScript code?
function equalto()
{
int num=10;
if(num===10)
return true;
else
return false;
}

A. true
B. false
C. runtime error
D. compilation error
Answer : A
44. What will be the output of the following Javascript code?
var a=3.7;
var b=2;
a=ciel(a)
document.writeIn(a*b);

A. 6
B. 7.4
C. 7.5
D. 8
Answer : D
45. When an empty statement is encountered, a JavaScript interpreter __________
A. Ignores the statement
B. Prompts to complete the statement
C. Throws an error
D. Shows a warning
Answer : A
46. What will be the output of the following JavaScript code?
int a=4;
int b=1;
int c=0;
If(a==b)
document.write(a);
else if(a==c)
document.write(a);
else
document.write(c);

A. 4
B. 1
C. Error
D. 0
Answer : D
47. Which of the following is not considered as an error in JavaScript?
A. Syntax error
B. Missing of semicolons
C. Division by zero
D. Missing of Bracket
Answer : C
48. What will happen if reverse() and join() methods are used simultaneously?
A. Reverses and stores in the same array
B. Reverses and concatenates the elements of the array
C. Reverses
D. Stores the elements of an array in normal order
Answer : A
49. Consider the following code snippet
function f(o)
{
if (o === undefined) debugger;
}

What could be the task of the statement debugger?

A. It does nothing but a simple breakpoint
B. It debugs the error in that statement and restarts the statements execution
C. It is used as a keyword that debugs the entire program at once
D. It is used to find error in the statement
Answer : A
50. Which is a more efficient JavaScript code snippet?
Code 1 :
for(var num=10;num>=1;num--)
{
document.writeln(num);
}

Code 2 :
var num=10;
while(num>=1)
{
document.writeln(num);
num++;
}

A. Code 1
B. Code 2
C. Both Code 1 and Code 2
D. Cannot Compare
Answer : A

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