Lesson 2: Writing Simple Scripts

Question 1

What is each script known as?

Answer 1

A statement.

Question 2

What should each statement end with?

Answer 2

A semi-colon ;

Question 3

What are comments used for?

Answer 3

To explain what your code does.

Question 4

Show a single line comment:

Answer 4

// single line comment

Question 5

Show a multiple line comment:

Answer 5

/* multiple line comment */

Question 6

What data types are there?

Answer 6

• Number : 3-5
• Boolean: true/false
• Undefined
• Null

Question 7

What are variables used for?

Answer 7

To store information temporarily in order to complete certain tasks.

Question 8

Declare a variable:

Answer 8

• vair quantity; // prior ES6
• let price; // variable
• const ratio; // constant

Question 9

What type are Strings in JavaScript?

Answer 9

Primitive.

Question 10

Use a string constructor to make a new string:

Answer 10

let str = new String(‘Hello’);

Question 11

What does ‘Escaping’ mean?

Answer 11

Making a regular char after \ special and making a special char after \ literal.

Question 12

Show escaping:

Answer 12

let question = ‘What/’s your name?’;

Question 13

What does the string operator + symbol do?

Answer 13

Joins strings on either side of it.

Question 14

Show concatenating strings:

Answer 14

let greeting = 'Hello';
let name = 'Bob'
let message = greeting + name;

Question 15

What are events?

Answer 15

The browser’s way of saying “Hey, this happened.”

Question 16

What are Arithmetic Operations?

Answer 16

Addition, subtraction, multiplication and division.

Question 17

Show an Arithmetic Operation:

Answer 17

var theSum = 4 + 3;

Question 18

Show an Arithmetic Operation using variable names:

Answer 18

var productCount = 2;
var subtotal = 14.98;
var shipping = 2.75;
var total = subtotal + shipping;

Question 19

Show an example of Combining Operators:

Answer 19

price = price * uplift;
price*= uplift

Question 20

How to convert Celsius to Fahrenheit?:

Answer 20

var hTemp = cTemp*9/5 + 32;

Question 21

Write a code snippet converting Celsius to Fahrenheit:

Answer 21

var hTemp = cTemp *9/5 + 32;

document. write(“Temp in C: + cTemp + “degrees<br></br>”);
document. write(Temp in F + hTemp + “degrees”);

Question 22

What are three event handlers?

Answer 22

onClick, onMouseOver and onMouseOut

Question 23

What can the onClick event handler do?

Answer 23

Be applied to nearly all HTML elements.

Question 24

Show an example of an onClick event handler:

Question 25

What do the onMouseOver and onMouseOut event handlers used for?

Answer 25

When you want to detect where the mouse pointer is on the screen with a reference to a page element.

Question 26

Show an example of onMouseOver:

Answer 26

<img></img>