Showing unique characters in a string only once

Question

I have a string with repeated letters. I want letters that are repeated more than once to show only once. For instance I have a string aaabbbccc i want the result to be abc.

Answer 1

Too late may be but still my version of answer to this post:

function extractUniqCharacters(str){
    var temp = {};
    for(var oindex=0;oindex<str.length;oindex++){
        temp[str.charAt(oindex)] = 0; //Assign any value
    }
    return Object.keys(temp).join("");
}