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
Correct Answer :
A. Code 1
Explanation: Code 1 would be more efficient. Infact second code will go into runtime error as the value of num will never reach less than or equal to one.
Related Questions
If you have a function f and an object o, you can define a method named m of o with
o.m=m.f;
o.m=f;
o=f.m;
o=f;
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
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
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
===
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
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
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 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
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 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]
A hexadecimal literal begins with __________
00
0x
0X
Both 0x and 0X
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
The reduce and reduceRight methods follow a common operation called __________
filter and fold
inject and fold
finger and fold
fold
What will be the output of the following Javascript code?
var a= 0;
var b = 0;
while (a < 3)
{
a++;
b += a;
console.log(b);
}
var b = 0;
while (a < 3)
{
a++;
b += a;
console.log(b);
}
135
123
013
01
JavaScript Code can be called by using ____________
RMI
Triggering Event
Preprocessor
Function/Method
Consider the following code snippet.
for(var p in o)
console.log(o[p]);
The above code is equivalent to which code?
console.log(o[p]);
for (var i = 0;i < a.length;i++)
console.log(a[i]);
for (int i = 0;i < a.length;i++)
console.log(a[i]);
for (var i = 0;i <= a.length;i++)
console.log(a[i]);
for (var i = 1;i < a.length;i++)
console.log(a[i]);
Consider the following code snippet.
for(var p in o)
console.log(o[p]);
The above code is equivalent to which code?
console.log(o[p]);
for (var i = 0;i < a.length;i++)
console.log(a[i]);
for (int i = 0;i < a.length;i++)
console.log(a[i]);
for (var i = 0;i <= a.length;i++)
console.log(a[i]);
for (var i = 1;i < a.length;i++)
console.log(a[i]);
A linkage of series of prototype objects is called as ________
prototype stack
prototype chain
prototype class
prototypes
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
Which of the operator is used to test if a particular property exists or not?
in
exist
within
exists
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);
var value = Math.max.apply(null, arr);
document.writeln(value);
7
5
1
9
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?
function range(int length)
{
int a=5;
for(int i=0;i<length;i++)
{
console.log(a);
}
}
range(3);
{
int a=5;
for(int i=0;i<length;i++)
{
console.log(a);
}
}
range(3);
5
555
3
error
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
One of the special feature of an interpreter in reference with the for loop is that ___________
Before each iteration, the interpreter evaluates the variable expression and assigns the name of the property
The iterations can be infinite when an interpreter is used
The body of the loop is executed only once
the iteration is finite when an interpreter is used
What will be the output of the following JavaScript code?
var person =
{
name: Rahul,
getName: function()
{
nreturn this.name;
}
}
var unboundName = person.getName;
var boundName = unboundName.bind(person);
document.writeln(boundName());
{
name: Rahul,
getName: function()
{
nreturn this.name;
}
}
var unboundName = person.getName;
var boundName = unboundName.bind(person);
document.writeln(boundName());
runtime error;
compilation error
Rahul
undefined
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
The script tag must be placed in __________
the head tag
the head or body
the title or head
after the body tag
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?
1.01
1.047
1.00
1.4