JavaScript is a _______________ language.
Object-Oriented
High-level
Assembly-language
Object-Based
Correct Answer :
D. Object-Based
Explanation: JavaScript is not a full-blown OOP (Object-Oriented Programming) language, such as Java or PHP, but it is an object-based language. The criteria for object orientation are the classic threesome of polymorphism, encapsulation and inheritance and JavaScript doesnt pass this.
Related Questions
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?
{
var len = a.length, i = 0;
if (len == 0)
console.log(Empty Array);
else
{
do
{
console.log(a[i]);
} while (++i < len);
}
}
Prints the numbers in the array in order
Prints the numbers in the array in the reverse order
Prints 0 to the length of the array
Prints Empty Array
A proper scripting language is a __________
High level programming language
Assembly level programming language
Machine level programming language
Low level programming language
The reduce and reduceRight methods follow a common operation called __________
filter and fold
inject and fold
finger and fold
fold
What will be the possible output of the following JavaScript code?
var a = [1,2,3,4,5];
a.slice(0,3);
a.slice(0,3);
Returns [1,2,3]
Returns [4,5]
Returns [1,2,3,4]
Returns [1,2,3,4,5]
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);
int b=1;
int c=0;
If(a==b)
document.write(a);
else if(a==c)
document.write(a);
else
document.write(c);
4
1
Error
0
What will happen if the body of a for/in loop deletes a property that has not yet been enumerated?
The property will be stored in a cache
The loop will not run
That property will not be enumerated
The property will be enumerated
The escape sequence stands for _________
Floating numbers
Representation of functions that returns a value
is not present in JavaScript
Form feed
The one-liner code that concatenates all strings passed into a function is
function concatenate()
{
return String.prototype.concat('', arguments);
}
function concatenate()
{
return String.prototype.apply('', arguments);
}
function concatenate()
{
return String.concat.apply('', arguments);
}
function concatenate()
{
return String.prototype.concat.apply('', arguments);
}
What will be the output of the following Javascript code?
int a=0;
for(a;a<5;a++);
console.log(a);
for(a;a<5;a++);
console.log(a);
0
error
4
5
Which is an equivalent code to invoke a function m of class o that expects two arguments x and y?
o(x,y);
o.m(x) && o.m(y);
m(x,y);
o.m(x,y);
What is the observation made in the following JavaScript code?
if (!a[i]) continue;
Skips the defined elements
Skips the existent elements
Skips the null elements
Skips the defined & existent elements
What will be the output of the following JavaScript code?
function info()
{
int a=1;
int b=2;
return a*b;
}
document.write(info());
{
int a=1;
int b=2;
return a*b;
}
document.write(info());
1
2
3
error
What will be the output of the following JavaScript code?
int a==2;
int b=4;
int ans=a+b;
print(ans);
int b=4;
int ans=a+b;
print(ans);
2
6
0
error
A linkage of series of prototype objects is called as ________
prototype stack
prototype chain
prototype class
prototypes
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;
}
{
for (; o.next; o = o.next) ;
return o;
}
No, this will throw an exception as only numerics can be used in a for loop
No, this will not iterate
Yes, this will work
No, this will result in a runtime error with the message Cannot use Linked List
The enumeration order becomes implementation dependent and non-interoperable if ___________
If the object inherits enumerable properties
The object does not have the properties present in the integer array indices
The delete keyword is never used
Object.defineProperty() is not used
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?
{
if (a == 1)
continue;
else
a++;
}
The continue keyword restarts the loop
The continue keyword skips the next iteration
The continue keyword skips the rest of the statements in that iteration
The continue keyword breaks out of the loop
The snippet that has to be used to check if a is not equal to null is _________
if(a!=null)
if (!a)
if(a!null)
if(a!==null)
The main purpose of a Live Wire in NetScape is to ________
Create linkage between client side and server side
Permit server side, JavaScript code, to connect to RDBMS
Support only non relational database
To interpret JavaScript code
Among the keywords below, which one is not a statement?
debugger
with
if
use strict
What will be the output of the following JavaScript code?
const obj1 =
{
property1: 21
}
const descriptor1 = Object.getOwnPropertyDescriptor(obj1, 'property1');
console.log(descriptor1.configurable);
console.log(descriptor1.enumerable);
{
property1: 21
}
const descriptor1 = Object.getOwnPropertyDescriptor(obj1, 'property1');
console.log(descriptor1.configurable);
console.log(descriptor1.enumerable);
true 21
true false
true true
false false
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 ____________
var pattern = /d+/g // Matches all instances of one or more digits
text==pattern
text.equals(pattern)
text.test(pattern)
pattern.test(text)
What will be the shift() output of the following JavaScript code?
var a = [];
a.unshift(1);
a.unshift(22);
a.shift();
a.unshift(3,[4,5]);
a.shift();
a.shift();
a.shift();
a.unshift(1);
a.unshift(22);
a.shift();
a.unshift(3,[4,5]);
a.shift();
a.shift();
a.shift();
1
[4,5]
[3,4,5]
Exception is thrown
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
}
};
main title: JavaScript,
'sub-title': The Definitive Guide,
for: all audiences,
author: {
firstname: David,
surname: Flanagan
}
};
properties
property values
property names
objects
What will be the output of the following JavaScript code?
const object1 = {};
a = Symbol('a');
b = Symbol.for('b');
object1[a] = 'harry';
object1[b] = 'derry';
const objectSymbols = Object.getOwnPropertySymbols(object1);
console.log(objectSymbols.length);
a = Symbol('a');
b = Symbol.for('b');
object1[a] = 'harry';
object1[b] = 'derry';
const objectSymbols = Object.getOwnPropertySymbols(object1);
console.log(objectSymbols.length);
0
2
1
Error
What will be the output of the following JavaScript code?
int a=1;
if(a!=null)
return 1;
else
return 0;
if(a!=null)
return 1;
else
return 0;
1
0
runtime error
compiler error
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?
{
if (a == 1)
continue;
else
a++;
}
The continue keyword restarts the loop
The continue keyword skips the next iteration
The continue keyword skips the rest of the statements in that iteration
The continue keyword breaks out of the loop
What are the three important manipulations done in a for loop on a loop variable?
Updation, Incrementation, Initialization
Initialization,Testing, Updation
Testing, Updation, Testing
Initialization,Testing, Incrementation
What will be the output of the following JavaScript code?
function equalto()
{
int num=10;
if(num===10)
return true;
else
return false;
}
{
int num=10;
if(num===10)
return true;
else
return false;
}
true
false
runtime error
compilation error
What is the observation made in the following JavaScript code?
var count = [1,,3];
The omitted value takes undefined
This results in an error
This results in an exception
The omitted value takes an integer value