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
Correct Answer :
B. goodday
Explanation: The + operator acts as a concatenation operator when used with string. The new string does not have any space between the two added string.
Related Questions
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
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
What will be the output of the following JavaScript code?
string a = hi;
string b =there;
alert(a+b);
string b =there;
alert(a+b);
hi
there
hithere
undefined
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?
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
What is the prototype represents in the following JavaScript code snippet?
function f() {};
Function f
A custom constructor
Prototype of a function
Not valid
What will be the output of the following JavaScript code?
int sum=0;
var arr = [10,15,20,30];
arr.forEach(function myFunction(element)
{
sum= sum+element;
});
document.writeln(sum);
var arr = [10,15,20,30];
arr.forEach(function myFunction(element)
{
sum= sum+element;
});
document.writeln(sum);
70
75
10
error
When an empty statement is encountered, a JavaScript interpreter __________
Ignores the statement
Prompts to complete the statement
Throws an error
Shows a warning
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
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
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?
var count = [1,,3];
The omitted value takes undefined
This results in an error
This results in an exception
The omitted value takes an integer value
JavaScript is a _______________ language.
Object-Oriented
High-level
Assembly-language
Object-Based
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;
}
default:
result+= 0;
}
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
What happens in the following javaScript code snippet?
var count = 0;
while (count < 10)
{
console.log(count);
count++;
}
while (count < 10)
{
console.log(count);
count++;
}
The values of count are logged or stored in a particular location or storage
The value of count from 0 to 9 is displayed in the console
An error is displayed
An exception is thrown
What will be the equivalent output of the following JavaScript code snippet?
x = ~-y;
w = x = y = z;
q = a?b:c?d:e?f:g;
w = x = y = z;
q = a?b:c?d:e?f:g;
x = ~(-y); w = (x = (y = z));
q = a?b:(c?d:(e?f:g));
x = a?b:(c?d:(e?f:g));
q = ~(-y); w = (x = (y = z));
x = (x = (y = z));w = ~(-y);
q = a?b:(c?d:(e?f:g));
x = ~(-y); w = (x = (y = z));
q = (c?d:(e?f:g));
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
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 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
What will be the output of the following JavaScript code?
const obj1 = { property1: '10'};
const obj2 = Object.freeze(obj1);
obj2.property1 = '20';
console.log(obj2.property1);
const obj2 = Object.freeze(obj1);
obj2.property1 = '20';
console.log(obj2.property1);
10
20
Runtime error
Compilation error
Among the keywords below, which one is not a statement?
debugger
with
if
use strict
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?
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
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
What will be the output of the following JavaScript code?
125
25
5
Error
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
A conditional expression is also called a _______________
Alternative to if-else
Immediate if
If-then-else statement
Switch statement
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 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
The var and function are __________
Keywords
Declaration statements
Data types
Prototypes