Question

IN RUBY LANGUAGE.

Write a single Ruby demo program that illustrates the use of all main Ruby iterators (loop, while, until, for, upto, downto, times, each, map, step, collect, select, reject). The program should have a few lines illustrating loop, followed by a few lines illustrating while, and so on).

PLEASE HAVE COPYABLE CODE. NOT A PICTURE. THANK YOU.

Answer 1

Loop

i = 0
loop do
  i += 1
  puts i
  break         # this will cause execution to exit the loop
end

While:

x = 4

# using while loop

# here conditional is x i.e. 4

while x >= 1

# statements to be executed

  puts "Hi"

  x = x - 1

# while loop ends here

end

FOR:

i = "YO"

# using for loop with the range

for a in 1..5 do    

puts i

end

Until:

var = 7

# using until loop

# here do is optional

until var == 11 do

  # code to be executed

  puts var * 10

  var = var + 1

# here loop ends

end

EACH:

# using each iterator

# here collection is range

# variable name is i

(0..9).each do |i|     

    # statement to be executed

    puts i    

end

Collect:

a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

  

# using collect iterator

# printing table of 5

b = a.collect{ |y| (5 * y) }

puts b

TIMES:

# using times iterator by providing

# 7 as the iterate value

7.times do |i|

    puts i

end

UPTO:

# using upto iterator

# here top value is 4

# bottom value is 7

4.upto(7) do |n|   

  puts n   

end  

  

# here top > bottom

# so no ouput

7.upto(4) do |n|   

  puts n   

end  

DOWNTO:

# using downto iterator

# here top value is 7

# bottom value is 4

7.downto(4) do |n|   

  puts n   

end  

  

# here top < bottom

# so no output

4.downto(7) do |n|   

  puts n   

end  

STEP:

# using step iterator

# skipping value is 10

# (0..60 ) is the range

(0..60).step(10) do|i|

    puts i

end

EACH_LINE:

# using each_line iterator

"Welcome\nto\nRailway\nPortal".each_line do|i|

puts i

end

MAP:

array = [1,2,3]

array.map { |n| n * 2 }

# [2, 4, 6] is output

STEP:

# Increment from 0 to 10, by 2 each time.

# ... Name the iteration variable "v".

0.step(10, 2) do |v|

   puts v

end

Collect:

# Ruby code for collect() method

  

# declaring array

a = [1, 2, 3, 4]

  

# invoking block for each element

puts "collect a : #{a.collect {|x| x + 1 }}\n\n"

Select:

  

# declaring array

c = [18, 22, 3, 3, 50, 6]

  

# select

puts "select method : #{a.select {|num| num > 10 }}\n\n"

Reject:

# declaring array

c = [18, 22, 3, 3, 50, 6]

  

# reject

puts "reject method : #{a.reject {|num| num > 10 }}\n\n"