javascript

Question 1

What is the advantage of external JavaScript?

Answer 1

Separates HTML and Code
Makes HTML and JavaScript easier to read and maintaiin
Cached JS files can speed up page loads

Question 2

Name the four ways of JavaScript Display Possibilites :

Answer 2

console.log() -browser console
window.alert() -alert box
document.write() -html element
innerHTML

Question 3

Write the code to change the id element named “demo” when the user clicks on a button.

Answer 3

<p>This will be changed</p>

Click

Question 4

<h1>My First Web Page</h1>

<p>My First Paragraph.</p>

<p></p>

Insert the sum of 5+5 inside the p tag.

Answer 4

var a =document.getElementById("demo");
a.innerHTML = 5+5;

Question 5

The JavaScript programs are executed by what?

Answer 5

the web browsers

Question 6

Can you name the javascript statements?

Answer 6

C : comment
O : operators
V : values
E : expressions
K : keywords

Question 7

What are the two types of JavaScript Values?

Answer 7

Fixed values and variable values.
fixed values : literals
variable values : variables

Question 8

Name the ways you can declare variables

Answer 8

var, let and const

Question 9

Difference between let and var?

Answer 9

var : known through out the function it is defined in

let : known thoughout the block it is defined in

Question 10

Is JavaScript case sensitive?

Answer 10

Yes

Question 11

What character set does javascript use?

Answer 11

Unicode

Question 12

How do you debug in javascript?

Answer 12

All moderns browsers have a build in javascript debugger.

F12 and console

Question 13

Name the 7 Javascript types.

Answer 13

Number
String
Boolean
function
Object
Null
Undefined

Question 14

How to create a javascript object?

Answer 14

var person ={firstname: “John”,

lastname: “Doe”,
age: 50};

Question 15

What is the typeof undefined?

Answer 15

undefined

Question 16

What is the datatype of null?

Answer 16

object

Question 17

what is null=== undefined?

Answer 17

false

Question 18

What is null==undefined?

Answer 18

true

Question 19

can u declare string as objects?

Answer 19

NOPE DONT DO IT

Question 20

Create an object.

Answer 20

Var person =
{
 name : 'nilima',
great : 'very great'
};

Question 21

What are the scopes in javascript?

Answer 21

local and global

Question 22

What is a scope?

Answer 22

the set of variables, objects and functions you have access to.

Question 23

What are the event listeners?

Answer 23

<div></div>

element. onclick=function(){}
element. addEventListener(“click”, function(){});

Question 24

What does event.stopPropogation()?

Answer 24

it will stop calling event handlers.

Question 25

What does event.target do?

Answer 25

Always points to the lowest element on the tree it was clicked.

Question 26

What is bubble?

Answer 26

bubble starts at the bottom of the tree and works its way up

Question 27

What is capture/

Answer 27

starts at the top and goes to the button

Question 28

Name the string method to uppercase?

Answer 28

toUpperCase();

Question 29

Name the string method to lowercase?

Answer 29

toLowerCase()

Question 30

What returns the Maximum value?

Answer 30

MAX_VALUE

Question 31

What returns the Minimum value?

Answer 31

MIN_VALUE

Question 32

What does Math.pow() do?

Answer 32

Math.pow(2,2)

2 to the power 2 = 4

Question 33

What does Math.sqrt() do?

Answer 33

square root of

Question 34

What does Math.ceil do? Math.ceil(4.7)

Answer 34

5

Question 35

What does Math.floor do? Math.floor(4.7)

Answer 35

4

Question 36

What doe Math.random() return?

Answer 36

from 0 - 1 any number decimals

Question 37

How to sort array?

Answer 37

array.sort();

Question 38

How to reverse array?

Answer 38

array.reverse();

Question 39

How to handle errors?

Answer 39

like java try catch

Question 40

What is an error?

Answer 40

An object that has two properties named name and message.

Question 41

Name error name values

Answer 41

6 different values

• EvalError
• RangeError
• ReferenceError
• SyntaxError
• TypeError
• URIError

Question 42

what is ajax?

Answer 42

Asynchronous JavaScript and XML.
The ability to send request from JS asynchronously
u send the request forget about it and when you get the response you handle it

Question 43

Name the four steps in AJAX

Answer 43

• create object
• define onreadystatechange function
• open request (method, url, async)
• send request

Question 44

What does JQUERY have?

Answer 44

a single global object

$ and jQuery

Question 45

How to write ajax in jquery?

Answer 45

$.ajax({method: "get",
url:"some url",
success : function(){},
error : " ",
complete : "" })