How to check if two words are anagrams

Question

I have a program that shows you whether two words are anagrams of one another. There are a few examples that will not work properly and I would appreciate any help, although if it were not advanced that would be great, as I am a 1st year programmer. "schoolmaster" and "theclassroom" are anagrams of one another, however when I change "theclassroom" to "theclafsroom" it still says they are anagrams, what am I doing wrong?

import java.util.ArrayList; public class AnagramCheck {     public static void main(String args[]) {         String phrase1 = "tbeclassroom";         phrase1 = (phrase1.toLowerCase()).trim();         char[] phrase1Arr = phrase1.toCharArray();          String phrase2 = "schoolmaster";         phrase2 = (phrase2.toLowerCase()).trim();         ArrayList<Character> phrase2ArrList = convertStringToArraylist(phrase2);          if (phrase1.length() != phrase2.length()) {             System.out.print("There is no anagram present.");         } else {             boolean isFound = true;             for (int i = 0; i < phrase1Arr.length; i++) {                 for (int j = 0; j < phrase2ArrList.size(); j++) {                     if (phrase1Arr[i] == phrase2ArrList.get(j)) {                         System.out.print("There is a common element.\n");                         isFound =;                         phrase2ArrList.remove(j);                     }                 }                 if (isFound == false) {                     System.out.print("There are no anagrams present.");                     return;                 }             }             System.out.printf("%s is an anagram of %s", phrase1, phrase2);         }     }      public static ArrayList<Character> convertStringToArraylist(String str) {         ArrayList<Character> charList = new ArrayList<Character>();         for (int i = 0; i < str.length(); i++) {             charList.add(str.charAt(i));         }         return charList;     } } 

Answer 1

Two words are anagrams of each other if they contain the same number of characters and the same characters. You should only need to sort the characters in lexicographic order, and determine if all the characters in one string are equal to and in the same order as all of the characters in the other string.

Here's a code example. Look into Arrays in the API to understand what's going on here.

public boolean isAnagram(String firstWord, String secondWord) {      char[] word1 = firstWord.replaceAll("[\\s]", "").toCharArray();      char[] word2 = secondWord.replaceAll("[\\s]", "").toCharArray();      Arrays.sort(word1);      Arrays.sort(word2);      return Arrays.equals(word1, word2); } 

Answer 2

Fastest algorithm would be to map each of the 26 English characters to a unique prime number. Then calculate the product of the string. By the fundamental theorem of arithmetic, 2 strings are anagrams if and only if their products are the same.