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
Correct Answer :
A. one
Explanation: shift is a predefined function in array library and works like a pop function. It pops the first value of the array and returns its value. Therefore the answer will be one.
Related Questions
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 pop() method of the array does which of the following task?
decrements the total length by 1
increments the total length by 1
prints the first element but no effect on the length
updates the element
What will be the output of the following Javascript code?
<script>
var x = 5;
var y = 2;
var z = x % y;
document.getElementById("demo").innerHTML = z;
</script>
var x = 5;
var y = 2;
var z = x % y;
document.getElementById("demo").innerHTML = z;
</script>
0
1
2
5
For the below mentioned code snippet:
var o = new Object();
The equivalent statement is:
var o = Object();
var o;
var o= new Object;
Object o=new Object();
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;
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123.56
190
tall
short
Which keyword is used to define the function in javascript?
void
int
function
main
What will be the output of the following JavaScript code?
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object1[b] = 'derry';
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0
2
1
Error
What will be the output of the following Javascript code?
var txt1 = good;
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goodday
error
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The loop will not run
That property will not be enumerated
The property will be enumerated
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function f(o)
{
if (o === undefined) debugger;
}
What could be the task of the statement debugger?
{
if (o === undefined) debugger;
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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
What will be the output of the following Javascript code?
int a=0;
for(a;a<5;a++);
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0
error
4
5
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Which is a more efficient JavaScript code snippet?
Code 1 :
for(var num=10;num>=1;num--)
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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
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What will be the output of the following JavaScript code?
var grade='E';
var result;
switch(grade)
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case 'A':
result+=10;
case 'B':
result+= 9;
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result+= 8;
default:
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document.write(result);
var result;
switch(grade)
{
case 'A':
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case 'B':
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case 'C':
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default:
result+= 0;
}
document.write(result);
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0
18
17
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src
ext
script
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What will be the possible output of the following JavaScript code?
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a.slice(0,3);
a.slice(0,3);
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Returns [4,5]
Returns [1,2,3,4]
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for(var p in o)
console.log(o[p]);
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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]);
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lock down objects into a known state and prevent outside tampering
to include new properties into the object
What will be the output of the following JavaScript code?
var grade='B';
var result;
switch(grade)
{
case 'A':
{
result+=10;
break;
}
case 'B':
{
result+= 9;
break;
}
case 'C':
{
result+= 8;
break;
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default:
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document.write(result);
var result;
switch(grade)
{
case 'A':
{
result+=10;
break;
}
case 'B':
{
result+= 9;
break;
}
case 'C':
{
result+= 8;
break;
}
default:
result+= 0;
}
document.write(result);
10
9
8
0
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
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some functions do not return any value
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var a=5 , b=1
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{
alert(b)
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var obj = { a : 10 }
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alert(b)
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10
Error
1
5
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directly into JS file and included into HTML
directly on the server page
directly into HTML pages
directly into the css file
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125
25
5
Error
What is the difference between the two lines given below ?
!!(obj1 && obj2);
(obj1 && obj2);
(obj1 && obj2);
Both the lines result in a boolean value True
Both the lines result in a boolean value False
Both the lines checks just for the existence of the object alone
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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
The reduce and reduceRight methods follow a common operation called __________
filter and fold
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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 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