Loops & Iterators in Ruby Examples (Tested with Ruby 1.9.3)

loops_iterators.rb

#!/usr/bin/ruby

## Count to 50
1.upto(50) {|n| puts n}

## Count Down to 1
50.downto(1) {|n| puts n}

## Count to 20
(1..20).each {|n| puts n}
## OR
(1..20).each do |n| 
	puts n
end

## Counts to 46
i = 0
until i === 46
	i += 1
	puts "We have #{i} of these."
end 

## Counts to 10
for i in 0..10
	puts "Count #{i}! Sound Off!"
end

## While Loops
i=1
while i < 11
  print "#{i} "
  i+=1
end

## Loop Break (Single Line)
i=0
loop do
  i+=1
  print "#{i} "
  break if i==10
end

## Next Keyword and skip 3
i=0
loop do
  i+=1
  next if i==3
  print "#{i} "
  break if i==10
end

## Infinite Redo Keyword (does not evaluate the terminating condition)
i=1
until i > 10
  print "#{i} "
  i+=1
  redo if i > 10
end

##################################################################

## Array Counter to 10
for value in [1,2,3,4,5,6,7,8,9,10]
  print "#{value} "
end

## Iterator
[1,2,3,4,5,6,7,8,9,10].each do |value| 
print "#{value} "
end

##Times Iterator (ZERO INDEX!)
101.times do |i| 
print "#{i}\n"
end