Chapter 2 - Data And Decisions

Question 0

What is a number?

Answer 0

A number, including floating points number

Question 1

What is a string?

Answer 1

A series of characters

Question 2

What is a boolean data?

Answer 2

True or false

Question 3

What are the 3 primitives data types?

Answer 3

String
Number
Boolean

Question 4

What is Null?

Answer 4

Even though a variable had been created, its current value is Null or nothing

Question 5

What is Undefined?

Answer 5

Indicates that something has not been defined and given a value

Question 6

How does string data must be encloses?

Answer 6

Between ‘ ‘ or “ “

Question 7

How to write a string like Paul’s character?

Answer 7

Document.write(“Paul’s character”)

Use the “ because there is a ‘ in the string

Question 8

What are escape séquences?

Answer 8

To use character that can’t be typed using a keyboard

Question 9

\b

Answer 9

Backspace

Question 10

\f

Answer 10

Form Feed

Question 11

\n

Answer 11

Newline

Question 12

\r

Answer 12

Carriage return

Question 13

\t

Answer 13

Tab

Question 14

'

Answer 14

Single quote

Question 15

"

Answer 15

Double quote

Question 16

\

Answer 16

Backslash

Question 17

\xNN

Answer 17

nN is a number from hexadecimal

Question 18

\uDDDD

Answer 18

DDDD is hexadecimal from Unicode

Question 19

+

Answer 19

Adds

Question 20

-

Answer 20

Substracts

Question 21

*

Answer 21

Multiply

Question 22

/

Answer 22

Divides

Question 23

%

Answer 23

Modulus

Question 24

–

Answer 24

Decrease By 1

Question 25

++

Answer 25

Increase By 1

Question 26

+ with non number

Answer 26

Concatenate

Question 27

How to name variable?

Answer 27

Camel notation anusToMouth

Question 28

Prompt()

Answer 28

Ask the user a value and returns it to the code

Var eurosToConvert = prompt(“How many…”, “”);

Question 29

Typeof()

Answer 29

Know the type of data

Question 30

Number()

Answer 30

Tries to convert to number

Question 31

Parsefloat()

Answer 31

Tries to convert to a floating number. Or NaN

Question 32

ParseInt()

Answer 32

To an integer

Question 33

3 objects from javascript

Answer 33

String
Date
Math

Question 34

How to create a string object?

Answer 34

Implicit and explicit

Question 35

Object.length

Answer 35

Give the length of a string object

Question 36

Explicit string?

Answer 36

Var MyStringObject = new String( “abc” );

Question 37

UserEmail.indexOf( “@” ); ?

Answer 37

Return -1 if No @ found

Question 38

myOldString.substring( 2, 5);

Answer 38

Return character 3 to 5 because it starts at 0 and doesn’t include the last one (5)

Question 39

How can I create Date objects?

Answer 39

Only explicitely
Var todaysdate = new Date();

Question 40

How to specify the month of a date?

Answer 40

3 First letter

Question 41

Date object parameter

Answer 41

Var someDate = new Date( aYear, aMonth, aDate, anHour, aMinute, aSecond, aMillisecond)

Question 42

Where does date month start count ing?

Answer 42

0

Question 43

Date objects method?

Answer 43

getXXXX and setXXXX

Question 44

What does setDate(32); so?

Answer 44

Go to the next month (useful to add days)

Question 45

How to create a math object?

Answer 45

Only implicitely

Question 46

Does the math object store data?

Answer 46

No

Question 47

How to call a math object method?

Answer 47

Math.methodOfMathObject( aNumber )

Question 48

Math.parseInt()

Answer 48

Remove the decimals

Question 49

Math.round()

Answer 49

Round as usual

Question 50

Math.ceil()

Answer 50

Always round up

Question 51

Math.floor()

Answer 51

Rounds down

Question 52

Math.random()

Answer 52

Random between 0 and 1

Question 53

Use of an Array?

Answer 53

Store data

Question 54

How to initialize an Array?

Answer 54

Var preInitArray = new Array(“First Item”, “Second Item”, “Third Item”);

Question 55

How to Set an Array to hold 3 items?

Answer 55

Var PreDeterminedSizeArray = new Array( 3 );

Question 56

How to create an Empty Array?

Answer 56

Var anArray = new Array();

Question 57

How to add new items to an Array?

Answer 57

anArray[0] = "anItem";
anArray[1] = "anotherItem";

Question 58

Shortcut notation to add to an Array?

Answer 58

Var myArray = [ 1, 2, 3];