performance - In java whats the most efficient way to remove duplicate characters from string? -

i have helper function finds indexes of duplicate characters in string. whats best way remove these duplicates? thanks!

this best way know it. takes string, separates characters, put hashset (nonrepeating, ordered) , prints (or return string.

this best way out of ones listed

string example = "thiscode"; char[] chars = example.tochararray(); set<character> str = new linkedhashset<character>(); (char c : chars) {     str.add(c); }  stringbuilder sb = new stringbuilder(); (character character : str) {     sb.append(character); } system.out.println(sb.tostring()); 

alternatively:

public static string convert(string example){     char[] chars = example.tochararray();     set<character> str = new linkedhashset<character>();     (char c : chars) {         str.add(c);     }      stringbuilder sb = new stringbuilder();     (character character : str) {         sb.append(character);     }     return sb.tostring(); } 

another way it:

    string example = "thiscode";     stringbuilder sb = new stringbuilder(example);     (int i=0; i<example.length(); i++)                            //itterate throught characters         if (!sb.tostring().contains(example.charat(i) + ""))          //determine if in stringbuilder             sb.append(example.charat(i));                             //if not add     example = sb.tostring();                                          //take result     system.out.println(example); 

inefficient, easy implementation

string example = "thiscode"; string empty = ""; boolean alphabet[] = new boolean[26]; (char c : example.tochararray())     if (alphabet[(int) ((c + "").tolowercase().charat(0) - 'a')] == false)         empty += c; example = empty; system.out.println(example); 

hope helps.