Easiest way of checking if a string consists of unique characters?
- by serg555
I need to check in Java if a word consists of unique letters (case insensitive). As straight solution is boring, I came up with:
For every char in a string check if indexOf(char) == lastIndexOf(char).
Add all chars to HashSet and check if set size == string length.
Convert a string to a char array, sort it alphabetically, loop through array elements and check if c[i] == c[i+1].
Currently I like #2 the most, seems like the easiest way. Any other interesting solutions?