The method or operator used to identify the array is __________
isarrayType()
==
===
typeof
Correct Answer :
D. typeof
Explanation: The typeof operator is used to get the data type (returns a string) of its operand. The operand can be either a literal or a data structure such as a variable, a function, or an object. The operator returns the data type.
Related Questions
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 of the following is not considered as an error in JavaScript?
Syntax error
Missing of semicolons
Division by zero
Missing of Bracket
What will be the output of the following JavaScript code?
var values=[one,two,Three];
var ans=values.shift();
document.writeln(ans);
var ans=values.shift();
document.writeln(ans);
one
two
three
error
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;
}
{
int num=2;
char b=2;
if(a==b)
return true;
else
return false;
}
true
false
runtime error
compilation error
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
The basic purpose of the toLocaleString() is to _________
return a localised object representation
return a parsed string
return a local time in the string format
return a localized string representation of the object
What will be the output of the following JavaScript code?
function compare()
{
int a=1;
char b=1;
if(a.tostring()===b)
return true;
else
return false;
}
{
int a=1;
char b=1;
if(a.tostring()===b)
return true;
else
return false;
}
true
false
runtime error
logical error
Consider the following code snippet :
var tensquared = (function(x) {return x*x;}(10));
Will the above code work ?
Yes, perfectly
Error
Exception will be thrown
Memory leak
Which of the operator is used to test if a particular property exists or not?
in
exist
within
exists
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 arr=[1,2,3];
var rev=arr.reverse();
document.writeln(rev);
var rev=arr.reverse();
document.writeln(rev);
1, 2, 3
3, 2, 1
3
1
The property of a primary expression is ____________
stand-alone expressions
basic expressions containing all necessary functions
contains variable references alone
contains only keywords
Which attribute is used to specify that the script is executed when the page has finished parsing? (only for external scripts)
parse
a sync
defer
type
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
function f(o)
{
if (o === undefined) debugger;
}
What could be the task of the statement debugger?
{
if (o === undefined) debugger;
}
It does nothing but a simple breakpoint
It debugs the error in that statement and restarts the statements execution
It is used as a keyword that debugs the entire program at once
It is used to find error in the statement
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?
Int a=1;
if(a>10)
{
document.write(10);
}
else
{
document.write(a);
}
if(a>10)
{
document.write(10);
}
else
{
document.write(a);
}
10
0
1
Undefined
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
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
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 step of the interpreter in a jump statement when an exception is thrown?
The interpreter stops its work
The interpreter throws another exception
The interpreter jumps to the nearest enclosing exception handler
The interpreter throws an 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 function with no return value is called ___________
Procedures
Method
Static function
Dynamic function
The object has three object attributes namely ________
Class, parameters, objects extensible flag
Prototype, class, objects parameters
Prototype, class, objects extensible flag
Native object, Classes and Interfaces and Objects extensible flag
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
Consider the following code snippet :
var grand_Total=eval(10*10+5);
The output for the above statement would be :
10*10+5
105 as a string
105 as an integer value
Exception is thrown
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);
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);
var val2=[6,7,8];
var result=val1.concat(val2);
document.writeln(result);
1, 2, 3
Error
1, 2, 3, 6, 7, 8
123
What will be the output of the following Javascript code?
<script>
document.getElementById("demo").innerHTML = typeof "John"
</script>
document.getElementById("demo").innerHTML = typeof "John"
</script>
integer
number
string
error
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 ?
{
var funcs = [];
for(var i = 0; i < 10; i++)
funcs[i] = function() { return i; };
return funcs;
}
var funcs = constfuncs();
funcs[5]()
9
0
10
None of the mentioned