Codecademy Ruby 1

Question 1

What’s a boolean?

Answer 1

A true or false statement

Question 2

It’s also important to remember that Ruby is..

Answer 2

case-sensitive

Question 3

never use _______ with booleans,

Answer 3

quotation marks (‘ or “) or Ruby will think you’re talking about a string (a word or phrase)

Question 4

What’s the name of this kinda thing? 2**8

Answer 4

exponentiation

Question 5

What’s an easier way to do 222

Answer 5

2**3

Question 6

What’s the name of the operator that returns the remainder of division?

Answer 6

Modulo

Question 7

What’s 25 % 7?

Answer 7

4

Question 8

What’s the difference between print and puts?

Answer 8

puts adds inserts a blank line after the output

Question 9

Everything in Ruby is an _______ with built in ____

Answer 9

object / method

Question 10

Editor>______>console

Answer 10

interpreter

Question 11

Display the number of characters in ‘Tom’

Answer 11

puts “tom”.length

Question 12

method for reversing values

Answer 12

.reverse

Question 13

method for changing case

Answer 13

.upcase and .downcase

Question 14

what do you use for a multi-line comment?

Answer 14

=begin
comment
yes yes yes
=end

(no space between the = and begin. Maths is ok either way with that though)

Question 15

what’s the convention for variables in Ruby?

Answer 15

lower case with _ between words, with no other symbols

Question 16

what character do you use to set variables?

Answer 16

=

Question 17

what’s do you call a positive or negative number with no decimal bit?

Answer 17

an integer

Question 18

what operator do you use to call a string?

Answer 18

.

For example “string”.method

Question 19

method to get inputs

Answer 19

gets

Question 20

method to remove the line break added automatically when receiving user input

Answer 20

.chomp

Question 21

how do you print a variable into a string

Answer 21

{variable}

Question 22

what do you call when a variable is replaced with a bit of information?

Answer 22

string interpolation

Question 23

what’s the method for capitalising the first letter of a string?

Answer 23

.capitalise

Question 24

what do you use to change the value of a variable inside itself?

Answer 24

!

Question 25

a fancy word for something that has a value that evaluates to either true or false

Answer 25

expression

Question 26

the convention for spacing inside an if statement

Answer 26

two spaces (not tabs)

Question 27

use to add more options to an else/if statement

Answer 27

elsif (NOT elseif)

Question 28

in ruby, what can you use instead of checking whether something is negative using an if statement? (maybe just used for booleans?)

Answer 28

unless

for example:
unless hungry
–code

(hungry would have to be set to true for the code to execute)

Question 29

what do you use instead of = as a comparator (otherwise called a rational operator)?

Answer 29

==

Question 30

not equal to

Answer 30

!=

Question 31

greater or equal to

Answer 31

> =

Question 32

less than or equal to

Answer 32

<=

Question 33

What is a boolean operator?

Answer 33

Boolean operators result in boolean values: true or false.

Question 34

What does && do?

Answer 34

The boolean operator and, &&, only results in true when both expression on either side of && are true.

Question 35

or operator

Answer 35

||

Ruby’s or operator evaluates to true when either or both of the values are true… called an inclusive

Question 36

not true

Answer 36

!true

Question 37

what would this equate to?

!(700 / 10 == 70)

Answer 37

false

because ! is a boolean operator

Question 38

(x && (y || w)) && z

Expressions ____ parentheses are always evaluated before anything ____ parentheses.

Answer 38

Expressions in parentheses are always evaluated before anything outside parentheses.

Question 39

What are the three boolean operators in Ruby?

Answer 39

&&, || and !

Question 40

what is a float?

Answer 40

a number with a decimal

Question 41

change gets to get an integer input

Answer 41

gets.to_i

Question 42

change gets to get a float input

Answer 42

gets.to_f

Question 43

generate a random floating point number between 0 and 1

Answer 43

rand()

Question 44

generate an integer between 0 and 10

Answer 44

rand(10)

Question 45

generate an integer between 20 and 100

Answer 45

rand(20..100)

Question 46

create a while loop

Answer 46

while

end

Question 47

how to you convert an integer to a string?

Answer 47

.to_s

Question 48

how to you make the code wait for 1 sec?

Answer 48

sleep 1