Loops & Iterators

Question 1

while

Answer 1

repeats an action while a statement is true ie. 
counter = 1
while counter < 11
  puts counter
  counter = counter + 1
end

Question 2

until

Answer 2

repeats an action until a function is true

Question 3

+=

Answer 3

increase a variable by a certain amount in each repetition

i.e. i + i += 1

Question 4

for

Answer 4

i.e. for every number in a sequence do the following

i.e.
for num in 1…10
puts num
end

Question 5

…

Answer 5

exclusive range.

i.e. 1… 10 will not include 10

Question 6

..

Answer 6

inclusive range

i.e. 1.. 10 will include 10

Question 7

loop

Answer 7

loops an action

i.e. loop { print “hello World!” }

Question 8

do, end

Answer 8

replaces the { } , opens an action and closes an action

Question 9

next

Answer 9

skips an action if condition is true

Question 10

break

Answer 10

breaks a loop if a condition is true

Question 11

array

Answer 11

a range of values all assigned to one variable

i. e. [1, 2, 3, 4, 5]
i. e. [ “a”, “e”, “i”]

Question 12

.each

Answer 12

performs a function on each element of an array

i.e.
array = [1,2,3,4,5]

array.each do |x|
x += 10
puts “#{x}”
end

Question 13

.times

Answer 13

repeats a function a specified number of times

i.e. 5.times { print “I love you”}

Question 14

.split

Answer 14

takes in a string and returns an array

Question 15

index

Answer 15

each value in an array has an index number starting from 0, 1, 2, 3….

i.e
my_array = [hi, my, name, is, jordan]

array [2]

returns -> name

Question 16

multidimensional array

Answer 16

arrays within arrays

ie.
multi_d_array = [[0,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,0]]

Question 17

hash

Answer 17

a substitute for using default numerical indices in arrays. (remember index on an array). You can assign custom values to keys using any object for boh the key and the value.

ie
hash = { “name” = “Eric” }

print hash [“name”]

returns > Eric

Question 18

Hash.new

Answer 18

setting a variable equal to Hash.new creates a new, empty hash.

** remember to always capitalize Hash

pets = Hash.new

pets[“Luna”] = “cat”

puts pets[“Luna”]

returns > cat

Question 19

Iterating over arrays

Answer 19

languages = [“HTML”, “CSS”, “JavaScript”, “Python”, “Ruby”]

languages.each { |code| puts code }

prints out
HTML
CSS
JavaScript
Python
Ruby

Question 20

iterating over a hash

Answer 20

lunch_order = {
  "Ryan" => "wonton soup",
  "Eric" => "hamburger",
  "Jimmy" => "sandwich",
  "Sasha" => "salad",
  "Cole" => "taco"
}

lunch_order.each do |name, order|
puts “#{order}”
end

returns:
wonton soup
hamburger
sandwich
salad
taco

Question 21

.to_s

Answer 21

converts a value to a string