method for expand a-z to abc…xyz form

Question

Hi:) what i\'m trying to do is write a simple program to expand from shortest entry

for example

a-z or 0-9 or a-b-c or a-z0-9

Answer 1

Based on the fact that the existing function addresses "a-z" and "0-9" sequences just fine, separately, we should explore what happens when they meet. Trace your code (try printing each variable's value at each step -- yes it will be cluttered, so use line breaks), and I believe you will find a logical short-circuit when iterating, for example, from "current token is 'y' and next token is 'z'" to "current token is 'z' and next token is '0'". Explore the if() condition and you will find that it does not cover all possibilities, i.e. you have covered yourself if you are within a<-->z, within 0<-->9, or exactly equal to '-', but you have not considered being at the end of one (a-z or 0-9) with your next character at the start of the next.