StrtoInt.rb

=begin

t can be used like this:

parseInt("10") returns 10
parseInt("10 apples") also returns 10
We would like it to return "NaN" (as a string) for the second case because the
input string is not a valid number.

You are asked to write a myParseInt method with the following rules:

It should make the conversion if the given string only contains a single integer
value (and eventually spaces - including tabs, line feeds... - at both ends)
For all other strings (including the ones representing float values), it should
return NaN
It should assume that all numbers are not signed and written in base 10

=end

# My Solution
def my_parse_int(string)
  string.strip =~ /^\d{1,}$/ ? string.to_i : "NaN"
end

# Another Solution
def my_parse_int(string)
  string.strip.match(/\D+/) ? "NaN" : string.to_i
end