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IBPS SO - JavaScript 1000+ MCQ [Solved] PDF Download

Thursday 9th of March 2023

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1. In the following syntax, the data type within the square brackets must be ___________
book[datatype]=assignment_value;

A. An integer
B. A String
C. An object
D. Floating point
Answer : B
2. Which is an equivalent code to invoke a function m of class o that expects two arguments x and y?
A. o(x,y);
B. o.m(x) && o.m(y);
C. m(x,y);
D. o.m(x,y);
Answer : D
3. What is the purpose of a return statement in a function?
A. Returns the value and continues executing rest of the statements, if any
B. Returns the value and stops the program
C. Returns the value and stops executing the function
D. Stops executing the function and returns the value
Answer : D
4. What will be the output of the following JavaScript code?
var a=5 , b=1
var obj = { a : 10 }
with(obj)
{
alert(b)
}

A. 10
B. Error
C. 1
D. 5
Answer : C
5. What will be the output of the following JavaScript code?
function output(object)
{
var place=object ? object.place : Italy;
return clean:+ place;
}
console.log(output({place:India}));

A. clean:India
B. clean:Italy
C. error
D. undefined
Answer : A
6. What will be the output of the following JavaScript code?

A. 7.25
B. -7.25
C. 7
D. -7
Answer : A
7. What will be the output of the following JavaScript code?

A. 125
B. 25
C. 5
D. Error
Answer : C
8. 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
9. 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
10. A conditional expression is also called a _______________
A. Alternative to if-else
B. Immediate if
C. If-then-else statement
D. Switch statement
Answer : B
11. 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
12. What will be the output of the following JavaScript code?
var arr=[1,2,3];
var rev=arr.reverse();
document.writeln(rev);

A. 1, 2, 3
B. 3, 2, 1
C. 3
D. 1
Answer : B
13. 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
14. 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
15. 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
16. What will be the output of the following JavaScript code?
var val1=[1,2,3];
var val2=[6,7,8];
var result=val1.concat(val2);
document.writeln(result);

A. 1, 2, 3
B. Error
C. 1, 2, 3, 6, 7, 8
D. 123
Answer : C
17. 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
18. JavaScript is ideal to ________
A. make computations in HTML simpler
B. minimize storage requirements on the web server
C. increase the download time for the client
D. increase the loading time of the website
Answer : B
19. 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
20. A linkage of series of prototype objects is called as ________
A. prototype stack
B. prototype chain
C. prototype class
D. prototypes
Answer : B
21. The var and function are __________
A. Keywords
B. Declaration statements
C. Data types
D. Prototypes
Answer : B
22. 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
23. The unordered collection of properties, each of which has a name and a value is called _________
A. String
B. Object
C. Serialized Object
D. Array
Answer : B
24. What will be the output of the following Javascript code?
var arr = [7, 5, 9, 1];
var min = Math.min.apply(null, arr);
document.writeln(min);

A. 7
B. 5
C. 1
D. 9
Answer : C
25. The generalised syntax for a real number representation is __________
A. [digits][.digits][(E|e)[(+|-)]digits]
B. [digits][+digits][(E|e)[(+|-)]digits]
C. [digits][(E|e)[(+|-)]digits]
D. [.digits][digits][(E|e)[(+|-)]digits]
Answer : A
26. 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
27. 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
28. Consider the following code snippet.
while (a != 0)
{
if (a == 1)
continue;
else
a++;
}

What will be the role of the continue keyword in the above code snippet?

A. The continue keyword restarts the loop
B. The continue keyword skips the next iteration
C. The continue keyword skips the rest of the statements in that iteration
D. The continue keyword breaks out of the loop
Answer : C
29. The primary purpose of the array map() function is that it __________
A. maps the elements of another array into itself
B. passes each element of the array and returns the necessary mapped elements
C. passes each element of the array on which it is invoked to the function you specify, and returns an array containing the values returned by that function
D. pass the elements of the array into another array
Answer : C
30. What will be the output of the following JavaScript code?

A. 1.01
B. 1.047
C. 1.00
D. 1.4
Answer : B
31. 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
32. Consider the following code snippet.
for(var p in o)
console.log(o[p]);

The above code is equivalent to which code?

A.
for (var i = 0;i < a.length;i++)
console.log(a[i]);

B.
for (int i = 0;i < a.length;i++)
console.log(a[i]);

C.
for (var i = 0;i <= a.length;i++)
console.log(a[i]);

D.
for (var i = 1;i < a.length;i++)
console.log(a[i]);

Answer : A
33. The function definitions in JavaScript begins with _____________
A. Identifier and Parentheses
B. Return type and Identifier
C. Retur type, Function keyword, Identifier and Parentheses
D. Identifier and Return type
Answer : C
34. What will be the step of the interpreter in a jump statement when an exception is thrown?
A. The interpreter stops its work
B. The interpreter throws another exception
C. The interpreter jumps to the nearest enclosing exception handler
D. The interpreter throws an error
Answer : C
35. One of the special feature of an interpreter in reference with the for loop is that ___________
A. Before each iteration, the interpreter evaluates the variable expression and assigns the name of the property
B. The iterations can be infinite when an interpreter is used
C. The body of the loop is executed only once
D. the iteration is finite when an interpreter is used
Answer : A
36. 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
37. A function with no return value is called ___________
A. Procedures
B. Method
C. Static function
D. Dynamic function
Answer : A
38. What will be the firstname and surname of the following JavaScript code?
var book = {
main title: JavaScript,
'sub-title': The Definitive Guide,
for: all audiences,
author: {
firstname: David,
surname: Flanagan
}
};

A. properties
B. property values
C. property names
D. objects
Answer : C
39. The method or operator used to identify the array is __________
A. isarrayType()
B. ==
C. ===
D. typeof
Answer : D
40. The statement a===b refers to _________
A. Both a and b are equal in value, type and reference address
B. Both a and b are equal in value
C. Both a and b are equal in value and type
D. There is no such statement
Answer : C
41. The type of a variable that is volatile is _______________
A. Volatile variable
B. Mutable variable
C. Immutable variable
D. Dynamic variable
Answer : B
42. What will be the output of the following JavaScript code?
function compare()
{
int num=2;
char b=2;
if(a==b)
return true;
else
return false;
}

A. true
B. false
C. runtime error
D. compilation error
Answer : A
43. 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
44. 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
45. Among the following, which one is a ternary operator?
A. +
B. :
C. ^
D. ?:
Answer : D
46. What will be the output of the following JavaScript code?
var arr = [7, 5, 9, 1];
var value = Math.max.apply(null, arr);
document.writeln(value);

A. 7
B. 5
C. 1
D. 9
Answer : D
47. 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
Answer : C
48. 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
49. 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
50. JavaScript can be written __________
A. directly into JS file and included into HTML
B. directly on the server page
C. directly into HTML pages
D. directly into the css file
Answer : A

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