Ruby Syntax

Question 1

How do you make a class?

Answer 1

class Name

attr_accessor :first, :second

  def initialize(first, second)
    @first = first
    @second = second
  end

end

Question 2

How do you make an array?

Answer 2

Dynamic Array:
array_name1 = []
array_name2 = Array.new()

Static Array:
array_name3 = [“One”, “Two”, “Three”]

Question 3

How do you write comments?

Answer 3

for single line comments

= begin

for block comments

=end

Question 4

How do you find the number of items in an array?

Answer 4

array_name.length

Question 5

How do you insert a variable into a string?

Answer 5

“This is a #{quote}”

Question 6

How do you write a while loop?

Answer 6

i = 0 (control variable)
count = 5

while i < count
DO SOMETHING
i += 1
end

Question 7

How do you write a for loop?

Answer 7

count = 5

for count in 0..4
DOES SOMETHING
end

Question 8

How do you write an until loop?

Answer 8

count = 0

begin
count += 1
end until (count==6)

Question 9

How do you write an each loop for arrays?

Answer 9

colors = [“red”, “blue”, “green”, “yellow”]

colors.each { |x| puts x}

Question 10

How do you write an if statement?

Answer 10

if CONDITION
  CONSEQUENT
else
  ALTERNATIVE
end

Question 11

How do you write an elsif statement?

Answer 11

if CONDITION 1
  CONSEQUENT 1
elsif CONDITION 2
  CONSEQUENT 2
else
  ALTERNATIVE
end

Question 12

How do you add items to an array?

Answer 12

array_name[n] = Value

array_name &laquo_space;Value

Question 13

How do you write a case statement?

Answer 13

count = 10

case count
  when 1..4
    action 1
  when 5
    action 2
  else
    ALTERNATIVE
 end

Question 14

How do you access values within a multidimensional array?

Answer 14

2d_array = [[1, 2, 3], [4, 5, 6]]

puts 2d_array[0][1]
It will print out 2

Question 15

How do you make an enumeration?

Answer 15

module Name
Thing1, Thing2, Thing3 = *1..3
end

Question 16

How do you open a file to read/write?

Answer 16

a_file = File.new(“file name”, “r”)

a_file = File.new(“file name”, “w”)

Question 17

How do you close a file?

Answer 17

a_file.close()

Question 18

How do you read from a file?

Answer 18

line_one = a_file.gets()
line_two = a_file.gets()
line_three = a_file.gets()