How do you determine if a String is a palindrome? [duplicate]

String palindrome = "..." // from elsewhere boolean isPalindrome = palindrome.equals(new StringBuilder(palindrome).reverse().toString()); 

public boolean checkPalindrome(string word){ for(int i=0 ; i < word.length()/2;i++) { if(word.charAt(i) ! = word.charAt(word.length()-1-i)) return false; } return true; } 

Noel's solution is actually better. But if it's for homework, you might want to do this:

public static boolean isPalindrome(String word) { int left = 0; int right = word.length() -1; while (left < right) { if (word.charAt(left) != word.charAt(right)) return false; left++; right--; } return true; } 

Java in-place palindrome check:

public static final boolean isPalindromeInPlace(String string) { char[] array = string.toCharArray(); int length = array.length-1; int half = Math.round(array.length/2); char a,b; for (int i=length; i>=half; i--) { a = array[length-i]; b = array[i]; if (a != b) return false; } return true; } 

String str="iai"; StringBuffer sb=new StringBuffer(str); String str1=sb.reverse().toString(); if(str.equals(str1)){ System.out.println("polindrom"); } else { System.out.println("not polidrom"); }