Ruby Code Explanation: Numbers to String using Recursion -

someone shared ruby code on how completed challenge have convert numbers words. solution far simplest read, not understand recursive aspect of it. specifically, in line below...

elsif int.to_s.length == 1 && int/num > 0   return str + "#{name}"  

if return statement breaks code out of loop, why wouldn't code execute , break loop once true? example, when int = 4 , num = 1, prove true , trigger return statement, yet code continues until num = 4.

any clarification on aspect of code, general advice understanding solution, helpful. still trying understand recursion. thanks

def in_words(int)   numbers_to_name = {       1000000 => "million",       1000 => "thousand",       100 => "hundred",       90 => "ninety",       80 => "eighty",       70 => "seventy",       60 => "sixty",       50 => "fifty",       40 => "forty",       30 => "thirty",       20 => "twenty",       19=>"nineteen",       18=>"eighteen",       17=>"seventeen",        16=>"sixteen",       15=>"fifteen",       14=>"fourteen",       13=>"thirteen",                     12=>"twelve",       11 => "eleven",       10 => "ten",       9 => "nine",       8 => "eight",       7 => "seven",       6 => "six",       5 => "five",       4 => "four",       3 => "three",       2 => "two",       1 => "one"     }    str = ""   numbers_to_name.each |num, name|     if int == 0       return str     elsif int.to_s.length == 1 && int/num > 0       return str + "#{name}"           elsif int < 100 && int/num > 0       return str + "#{name}" if int%num == 0       return str + "#{name} " + in_words(int%num)     elsif int/num > 0       return str + in_words(int/num) + " #{name} " + in_words(int%num)     end   end end  puts in_words(4) == "four" puts in_words(27) == "twenty seven" puts in_words(102) == "one hundred two" puts in_words(38_079) == "thirty 8 thousand seventy nine" puts in_words(82102713) == "eighty 2 million 1 hundred 2 thousand 7 hundred thirteen" 

debugging code

here's modified version debug lines in every branch :

def in_words(int, indent="")   puts "#{indent}in_words(#{int})"   numbers_to_name = {       1000000 => "million",       1000 => "thousand",       100 => "hundred",       90 => "ninety",       80 => "eighty",       70 => "seventy",       60 => "sixty",       50 => "fifty",       40 => "forty",       30 => "thirty",       20 => "twenty",       19=>"nineteen",       18=>"eighteen",       17=>"seventeen",        16=>"sixteen",       15=>"fifteen",       14=>"fourteen",       13=>"thirteen",                     12=>"twelve",       11 => "eleven",       10 => "ten",       9 => "nine",       8 => "eight",       7 => "seven",       6 => "six",       5 => "five",       4 => "four",       3 => "three",       2 => "two",       1 => "one"     }    str = ""   numbers_to_name.each |num, name|     puts "#{indent}  testing #{num}"     if int == 0       puts "#{indent}   empty string"       return str     elsif int.to_s.length == 1 && int/num > 0       puts "#{indent}  single digit found (#{name})!"       return str + "#{name}"           elsif int < 100 && int/num > 0       puts "#{indent}  double digits found (#{name})!"       return str + "#{name}" if int%num == 0       puts "#{indent}  recursive call #{int%num} :"       return str + "#{name} " + in_words(int%num, indent+"  ")     elsif int/num > 0       puts "#{indent}  recursive call #{int/num} , #{int%num} :"       indent += "  "       return str + in_words(int/num, indent) + " #{name} " + in_words(int%num,indent)     end   end end 

for in_words(4), outputs :

in_words(4)   testing 1000000   testing 1000   testing 100   testing 90   testing 80   testing 70   testing 60   testing 50   testing 40   testing 30   testing 20   testing 19   testing 18   testing 17   testing 16   testing 15   testing 14   testing 13   testing 12   testing 11   testing 10   testing 9   testing 8   testing 7   testing 6   testing 5   testing 4   single digit found (four)! 4 

and 27 :

in_words(27)   testing 1000000   testing 1000   testing 100   testing 90   testing 80   testing 70   testing 60   testing 50   testing 40   testing 30   testing 20   double digits found (twenty)!   recursive call 7 :   in_words(7)     testing 1000000     testing 1000     testing 100     testing 90     testing 80     testing 70     testing 60     testing 50     testing 40     testing 30     testing 20     testing 19     testing 18     testing 17     testing 16     testing 15     testing 14     testing 13     testing 12     testing 11     testing 10     testing 9     testing 8     testing 7     single digit found (seven)! twenty 7 

answer

for example, when int = 4 , num = 1, prove true , trigger return statement, yet code continues until num = 4.

with 4 input, num = 1 never happen. numbers_to_name in decreasing order, return statement happen num=4, , method won't execute other code after that.