Javascript online test, practice interview questions & answer

What will be the output of the below code?

0, 1, 2, 10

1, 2, 10

0, 1, 2, 2

1, 2, 3, 10

Hint

What is the correct output of the following JavaScript code?

var x = 0
do{ console.log(x) }while(x > 0)

null

No output

Is JavaScript a ECMAScript?

True

false

both

none

What does null means in JavaScript?

Null means empty string value.

Null means absence of a value.

Null means unknown value.

Null means zero value.

Which is NOT a correct way of declaring an array in JavaScript in following answers?

ar arr = [1, "two", 3 , 4 ];

var arr = new Array();

var[] arr = new Number()[5];

None of the above

What will be the output of the below code?

Init developer constructor

Init developer constructor, Init employee constructor

Init employee constructor

Init employee constructor, Init developer constructor

What will be the output of the below code?

test1@test.com, test2@test.com

0, 1,

email, email

What will the following statement return 1 == "1" ?

True

False

What will be the function? if a variable declared without var keyword inside function.

local

block

global

undefined

10.

Which is a valid JavaScript function in following answers?

var myFunc = function myFunc{ };

function myFunc(){ };

myFunc function(){ };

function myFunc = { };

11.

Which is NOT a JavaScript object in the following?

var obj = {};

var obj = { name: "Steve"};

var obj = { name = "Steve"};

var obj = new Object();

12.

Which is an example of anonymous function in JavaScript in the following answers?

var myFunc = function(){ };

function(){ };

var myFunc = (){ };

All of the above.

13.

How is strict mode in used to apply in JavaScript?

"apply strict"

"use strict"

"strict"

"strict mode"

14.

What does eval() means in JavaScript?

executes specified string as JavaScript code.

It will return an object representing the parsed tree of the specified JavaScript code.

It will execute server side code in JavaScript.

It will display popup message.

15.

How a error can be handled in JavaScript?

By using try, catch & finally block.

By using if-else block

By using eval().

By writing error proof code.