Sorting characters in a string into alphabetical order without arrays or maps (Java) -

i trying make program tests if 2 separate phrases anagrams of each other. this, want sort each string phrase alphabetical order , compare results. however, i want without using arrays or maps. far have pretty messy code/pseudocode:

import java.util.scanner;  public class anagramcomparer{   public static void main(string[] args){     scanner scan = new scanner(system.in);      system.out.println("enter sentence.");      string sentence = scan.nextline();          sentence = sentence.tolowercase();      string empty1 = "";      for(int = 0; <= sentence.length(); i++){        //if char between 97 & 122        // if char <= charat (0 sentence length - x)                       if(sentence.charat(i) <= empty1.charat(0)){         empty1.replace(empty1.charat(0), sentence.charat(i));                          }       else{          empty1 = (empty1 + (sentence.charat(i)));       }     }      system.out.println(empty1);     system.out.println(sentence);   } } 

the idea here run through string sentence character-by-character , sort alphabetically in string empty1. feel free tell me if i'm going in wrong direction; appreciated.

strings immutable, empty1.replace returns new string, doesn't modify existing one.

since string uses char[] internally, new string means new char[], you're still using arrays. might use own char[] better performance , lower memory footprint.

char[] chars = sentence.tolowercase().tochararray(); arrays.sort(chars);