The reduce and reduceRight methods follow a common operation called __________
filter and fold
inject and fold
finger and fold
fold
Correct Answer :
B. inject and fold
Explanation: The reduceRight() method reduces the array to a single value. The reduceRight() method executes a provided function for each value of the array (from right-to-left). The return value of the function is stored in an accumulator (result/total). Hence it does the operation of injecting and folding.
Related Questions
Among the keywords below, which one is not a statement?
debugger
with
if
use strict
What will happen if a return statement does not have an associated expression?
It returns the value 0
It will throw an exception
It returns the undefined value
It will throw an error
What will be the output of the following JavaScript code?
const obj = {prop: 12};
Object.preventExtensions(obj);
console.log( Object.isExtensible(obj));
Object.preventExtensions(obj);
console.log( Object.isExtensible(obj));
12
false
true
error
The escape sequence stands for _________
Floating numbers
Representation of functions that returns a value
is not present in JavaScript
Form feed
What will be the output of the following Javascript code?
<script>
txt1 = “ one”;
txt1 += “two”;
document.getElementById("demo").innerHTML = txt1;
</script>
txt1 = “ one”;
txt1 += “two”;
document.getElementById("demo").innerHTML = txt1;
</script>
onetwo
one two
error
undefined
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
A JavaScript program developed on a Unix Machine ________
will throw errors and exceptions
must be restricted to a Unix Machine only
will work perfectly well on a Windows Machine
will be displayed as a JavaScript text on the browser
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
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
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
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);
var result;
switch(grade)
{
case 'A':
result+=10;
case 'B':
result+= 9;
case 'C':
result+= 8;
default:
result+= 0;
}
document.write(result);
10
27
8
0
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
Consider the following code snippet :
var string2Num=parseInt(123xyz);
The result for the above code snippet would be :
123
123xyz
Exception
NaN
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
Among the following, which one is a ternary operator?
+
:
^
?:
What is the purpose of a return statement in a function?
Returns the value and continues executing rest of the statements, if any
Returns the value and stops the program
Returns the value and stops executing the function
Stops executing the function and returns the value
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
Do functions in JavaScript necessarily return a value?
It is mandatory
Not necessary
Few functions return values by default
some functions do not return any value
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 :
c.count()
d.count()
c.reset()
c.count()
d.count()
1
0
Null
Undefined
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
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
The statement a===b refers to _________
Both a and b are equal in value, type and reference address
Both a and b are equal in value
Both a and b are equal in value and type
There is no such statement
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);
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
An expression that can legally appear on the left side of an assignment expression. is a well known explanation for variables, properties of objects, and elements of arrays. They are called ___________
Properties
Prototypes
Lvalue
Definition
What will be the output of the following JavaScript code?
var pow=new Function(num1,num2,return Math.pow(num1,num2));
document.writeln(pow(2,3));
document.writeln(pow(2,3));
2
3
8
error
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
JavaScript _________ when there is an indefinite or an infinite value during an arithmetic computation.
Prints an exception error
Prints an overflow error
Displays Infinity
Prints the value as such
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
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