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@kylekeesling
Created November 12, 2015 21:08
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Output numbers into english words
def englishNumber number
if number < 0 # No negative numbers.
return 'Please enter a number that isn\'t negative.'
end
if number == 0
return 'zero'
end
# No more special cases! No more returns!
numString = '' # This is the string we will return.
onesPlace = ['one', 'two', 'three', 'four', 'five',
'six', 'seven', 'eight', 'nine']
tensPlace = ['ten', 'twenty', 'thirty', 'forty', 'fifty',
'sixty', 'seventy', 'eighty', 'ninety']
teenagers = ['eleven', 'twelve', 'thirteen', 'fourteen', 'fifteen',
'sixteen', 'seventeen', 'eighteen', 'nineteen']
# "left" is how much of the number we still have left to write out.
# "write" is the part we are writing out right now.
# write and left... get it? :)
left = number
write = left/1000 # How many thousands left to write out?
left = left - write*1000 # Subtract off those thousands.
if write > 0
thousands = englishNumber write
numString = numString + thousands + ' thousand'
if left > 0
numString = numString + ' '
end
end
write = left/100 # How many hundreds left to write out?
left = left - write*100 # Subtract off those hundreds.
if write > 0
# Now here's a really sly trick:
hundreds = englishNumber write
numString = numString + hundreds + ' hundred'
# That's called "recursion". So what did I just do?
# I told this method to call itself, but with "write" instead of
# "number". Remember that "write" is (at the moment) the number of
# hundreds we have to write out. After we add "hundreds" to
# "numString", we add the string ' hundred' after it.
# So, for example, if we originally called englishNumber with
# 1999 (so "number" = 1999), then at this point "write" would
# be 19, and "left" would be 99. The laziest thing to do at this
# point is to have englishNumber write out the 'nineteen' for us,
# then we write out ' hundred', and then the rest of
# englishNumber writes out 'ninety-nine'.
if left > 0
# So we don't write 'two hundredfifty-one'...
numString = numString + ' '
end
end
write = left/10 # How many tens left to write out?
left = left - write*10 # Subtract off those tens.
if write > 0
if ((write == 1) and (left > 0))
# Since we can't write "tenty-two" instead of "twelve",
# we have to make a special exception for these.
numString = numString + teenagers[left-1]
# The "-1" is because teenagers[3] is 'fourteen', not 'thirteen'.
# Since we took care of the digit in the ones place already,
# we have nothing left to write.
left = 0
else
numString = numString + tensPlace[write-1]
# The "-1" is because tensPlace[3] is 'forty', not 'thirty'.
end
if left > 0
# So we don't write 'sixtyfour'...
numString = numString + '-'
end
end
write = left # How many ones left to write out?
left = 0 # Subtract off those ones.
if write > 0
numString = numString + onesPlace[write-1]
# The "-1" is because onesPlace[3] is 'four', not 'three'.
end
# Now we just return "numString"...
numString
end
puts englishNumber( 0)
puts englishNumber( 9)
puts englishNumber( 10)
puts englishNumber( 11)
puts englishNumber( 17)
puts englishNumber( 32)
puts englishNumber( 88)
puts englishNumber( 99)
puts englishNumber(100)
puts englishNumber(101)
puts englishNumber(234)
puts englishNumber(1984)
puts englishNumber(3211)
puts englishNumber(999999)
puts englishNumber(1000000000000)
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