Introduction

Question 1

single line comment

Answer 1

comment

Question 2

single line comment

Answer 2

comment

Question 3

multi-line comment

Answer 3

=begin
this is 
a 
multi line
comment 
=end

Question 4

Boolean

Answer 4

true or false

Question 5

string

Answer 5

“just text”

Question 6

print

Answer 6

prints a value in the console

Question 7

puts

Answer 7

prints a value but adds a line break

Question 8

methods

Answer 8

a “skill” or feature of an objec

Question 9

.length

Answer 9

shows the length of characters in a string

Question 10

.reverse

Answer 10

reverses a string

Question 11

.upcase

Answer 11

capitalises an entire string

Question 12

.downcase

Answer 12

converts a string to all lowercase

Question 13

gets

Answer 13

retrieves user input

Question 14

.chomp

Answer 14

removes a blank line

Question 15

{variable}

Answer 15

retrieves variable data (user input) and inserts in a string

Question 16

if

Answer 16

evaluates something to true or false

Question 17

elsif

Answer 17

to insert another evaluations after an “if”

Question 18

else

Answer 18

evaluates everything else if the first “if” or “elsif” are false

Question 19

comparator

Answer 19

a sign that compares to values such as
== “is equal to”
< is less than

Answer 20

less than

Question 21

>

Answer 21

greater than

Question 22

<=

Answer 22

less than or equal to

Question 23

> =

Answer 23

greater than or equal to

Question 24

!=

Answer 24

not equal to

Question 25

==

Answer 25

equal to

Question 26

&&

Answer 26

and

Question 27

||

Answer 27

or

Question 28

!

Answer 28

not. reverses a true to false object to be the opposite

Question 29

unless

Answer 29

an unless function, another version of “if”

runs a function unless the following is true

Question 30

.gsub

Answer 30

substitutes a letter in a string ie
user_input.gsub (/s/, “th”)

the string “th” is what replaces every s

Question 31

end

Answer 31

ends a if, else function

Question 32

multi-line comment

Answer 32

=begin
this is 
a 
multi line
comment 
=end

Question 33

Boolean

Answer 33

true or false

Question 34

string

Answer 34

“just text”

Question 35

print

Answer 35

prints a value in the console

Question 36

puts

Answer 36

prints a value but adds a line break

Question 37

methods

Answer 37

a “skill” or feature of an objec

Question 38

.length

Answer 38

shows the length of characters in a string

Question 39

.reverse

Answer 39

reverses a string

Question 40

.upcase

Answer 40

capitalises an entire string

Question 41

.downcase

Answer 41

converts a string to all lowercase

Question 42

gets

Answer 42

retrieves user input

Question 43

.chomp

Answer 43

removes a blank line

Question 44

{variable}

Answer 44

String interpolation. retrieves variable data (user input) and inserts in a string

Question 45

if

Answer 45

evaluates something to true or false

Question 46

elsif

Answer 46

to insert another evaluations after an “if”

Question 47

else

Answer 47

evaluates everything else if the first “if” or “elsif” are false

Question 48

comparator

Answer 48

a sign that compares to values such as
== “is equal to”
< is less than

Answer 49

less than

Question 50

>

Answer 50

greater than

Question 51

<=

Answer 51

less than or equal to

Question 52

> =

Answer 52

greater than or equal to

Question 53

!=

Answer 53

not equal to

Question 54

==

Answer 54

equal to

Question 55

&&

Answer 55

and

Question 56

||

Answer 56

or

Question 57

!

Answer 57

not. reverses a true to false object to be the opposite

Question 58

unless

Answer 58

an unless function. an action runs unless a condition is true

Question 59

.gsub

Answer 59

substitutes a letter in a string ie
user_input.gsub (/s/, “th”)

the string “th” is what replaces every s

Question 60

end

Answer 60

ends a if, else function

Question 61

one-line If statement

Answer 61

an if statement can be written without and “end” if on one line

syntax
expression if boolean

ex.

puts “hello” if true

-> hello

Question 62

one-line unless statment

Answer 62

no need for end

i.e.
puts “hello” unless 2*3 == 5

-> hello

Question 63

ternary expression

Answer 63

a substitute for an if else statement. it takes three arguments: a boolean, an expression to evaluate if the boolean is true, and an expression to evaluate if the boolean is false.

syntax
boolean ? Do this if true: Do this if false

i.e.
puts 3 < 4 ? “3 is less than 4!” : “3 is not less than 4.”

Question 64

| =

Answer 64

conditional assignment operator. assigns a real value to a variable only when its current value is false of nil. Otherwise ruby keeps its original value

i.e.
boyfriend = nil

boyfriend ||= “Jimmy Jr.”

boyfriend ||= “Josh”

puts boyfriend
# => "Jimmy Jr."

Question 65

short circuit evuation

Answer 65

for boolean operators && or ||, ruby will only evaluate to the point it is sure whether the statement is true or false.

Question 66

.upto

Answer 66

iterates over values in a specific range upwards

i.e.
"B".upto("F") { |letter| print letter, " " }
# => B C D E F

Question 67

.downto

Answer 67

iterates over values in a specific range downwards

i.e
5.downto(0) { |num| print num, “ “ }
# => 5 4 3 2 1 0

Question 68

.respond_to?

Answer 68

takes a symbol representing a method name and returns true if that method can be called on the object and false otherwise.

puts "A".respond_to?(:push)
# => false
# Here, the following Ruby code will return false since .push can’t be called on a String object.

puts "A".respond_to?(:next)
# => true
# Here, however, the following Ruby code will return true since .next can be called on a String object. Calling .next on the letter “A” would return the letter “”.

Question 69

<

Answer 69

concatenation operator. an alternative to push. can be used to add an element to the end of an array or a string

array = [1, 2, 3]
array &laquo_space;4
print array
#Output => [1, 2, 3, 4]

puts "Hello," << " welcome to Codecademy."
#Output => Hello, welcome to Codecademy.