kacperk/ruby_koans — comment on commit 7861ad3c1c331d865731d966f5a506c720874f43
File: koans/about_regular_expressions.rb line 33
By kacperk:

? means that preceding symbol can appear (zero or one time)
+ means that preceding symbol must appear at least one time (one or more)
* means that preceding symbol can appear multiple time (zero or more)