Removing repeated characters in String

Question

I am having strings like this \"aaaabbbccccaaffffddcfggghhhh\" and i want to remove repeated characters get a string like this \"abcadcfgh\".

A simplistic implementati

Answer 1

You can use Java's String.replaceAll() method to simply do this with a regular expression.

String s = "aaaabbbccccaaffffddcfggghhhh";
System.out.println(s.replaceAll("(.)\\1{1,}", "$1")) //=> "abcadcfgh"

Regular expression

(               group and capture to \1:
 .              any character except \n
)               end of \1
\1{1,}          what was matched by capture \1 (at least 1 times)