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);
s = JSON.stringify(o);
p = JSON.parse(s);
Object Encapsulation
Object Serialization
Object Abstraction
Object Encoding
Correct Answer :
B. Object Serialization
Explanation: Object serialization is the process of converting an objects state to a string from which it can later be restored. The JSON.parse() method parses a JSON string, constructing the JavaScript value or object described by the string.
Related Questions
When does the function name become optional in JavaScript?
When the function is defined as a looping statement
When the function is defined as expressions
When the function is predefined
when the function is called
The var and function are __________
Keywords
Declaration statements
Data types
Prototypes
The method or operator used to identify the array is __________
isarrayType()
==
===
typeof
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
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
What will be the equivalent code of the following JavaScript code?
o.m(x,y);
o.m(x) && o.m(y);
o[m](x,y);
o(m)[x,y];
o.m(x && y);
To determine whether one object is the prototype of (or is part of the prototype chain of) another object, one should use the ____________
isPrototypeOf() method
equals() method
=== operator
==opertor
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);
var min = Math.min.apply(null, arr);
document.writeln(min);
7
5
1
9
What will be the output of the following Javascript code?
var a = 10;
do {
a += 1;
console.log(a);
} while (a < 5);
do {
a += 1;
console.log(a);
} while (a < 5);
11121314
1112
12345
11
What will be the output of the following JavaScript code?
function height()
{
var height = 123.56;
var type = (height>=190) ? tall : short;
return type;
}
{
var height = 123.56;
var type = (height>=190) ? tall : short;
return type;
}
123.56
190
tall
short
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
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
The primary purpose of the array map() function is that it __________
maps the elements of another array into itself
passes each element of the array and returns the necessary mapped elements
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
pass the elements of the array into another array
A hexadecimal literal begins with __________
00
0x
0X
Both 0x and 0X
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?
function printprops(o)
{
for(var p in o)
console.log(p + : + o[p] +
);
}
{
for(var p in o)
console.log(p + : + o[p] +
);
}
Prints the contents of each property of o
Returns undefined
Prints only one property
Prints the address of elements
In the following syntax, the data type within the square brackets must be ___________
book[datatype]=assignment_value;
An integer
A String
An object
Floating point
What will be the output of the following JavaScript code?
7.25
-7.25
7
-7
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
In the following switch syntax, the expression is compared with the case labels using which of the following operator(s)?
switch(expression)
{
statements
}
{
statements
}
==
equals
equal
===
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++;
}
{
document.writeln(num);
}
while(num>=1)
{
document.writeln(num);
num++;
}
Code 1
Code 2
Both Code 1 and Code 2
Cannot Compare
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++;
}
{
document.writeln(num);
}
while(num>=1)
{
document.writeln(num);
num++;
}
Code 1
Code 2
Both Code 1 and Code 2
Cannot Compare
Among the keywords below, which one is not a statement?
debugger
with
if
use strict
Assume that we have to convert false that is a non-string to string. The command that we use is (without invoking the new operator).
false.toString()
String(false)
String newvariable=false
Both false.toString() and String(false)
What will be the output of the following Javascript code?
var txt1 = good;
var txt2 = day;
document.getElementById(demo).innerHTML = txt1 + txt2;
var txt2 = day;
document.getElementById(demo).innerHTML = txt1 + txt2;
good day
goodday
error
undefined
What will be the output of the following Javascript code?
var add=new Function(num1,num2,return num1+num2);
document.writeln(add(2,5));
document.writeln(add(2,5));
2
5
Error
7
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)
What is a block statement in JavaScript?
conditional block
block that contains a single statement
both conditional block and a single statement
block that combines multiple statements into a single compound statement
Which keyword is used to define the function in javascript?
void
int
function
main