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What is Palindrome ?
A string is a palindrome if the position of each character is the same even if the string is reversed. For example, “NAMAN” is a palindrome because the position of each character is the same even if the string “NAMAN” is reversed. Here we can use the predefined library method or not, to identify a string as palindrome
Example – check if a given String is palindrome
public class PalindromeStringChecker { public static void main(String[] args) { String strValue = "NAMAN"; StringBuffer newStrValue = new StringBuffer(); for (int i = strValue.length() - 1; i >= 0; i--) { newStrValue = newStrValue.append(strValue.charAt(i)); } if (strValue.equalsIgnoreCase(newStrValue.toString())) { System.out.println(strValue + " is a palindrome String"); } else { System.out.println(strValue + " is not a palindrome String"); } } }
Output
NAMAN is a palindrome String
Example – check if a given String is palindrome using reverse method
public class PalindromeStringCheker { public static void main(String[] args) { String strValue = "NAMAN"; String reverseString = new StringBuffer(strValue).reverse()+""; if (strValue.equals(reverseString)) { System.out.println(strValue + " is palindrome String"); } else { System.out.println(strValue + " is not palindrome String"); } } }
Output
NAMAN is palindrome String
Example – Just another way
public class PalindromStringCheker { public static void main(String args[]) { String currentValue = ""; String compareValue = ""; currentValue = "545"; int length = currentValue.length(); for (int i = length - 1; i >= 0; i--) compareValue = compareValue + currentValue.charAt(i); if (currentValue.equals(compareValue)) { System.out.println(currentValue + " is a palindrome."); } else { System.out.println(currentValue + " is not a palindrome."); } } }
Output
545 is a palindrome.
Example
In above program, If: currentValue= "553" Output: 553 is not a palindrome. If: currentValue= “proedu” Output: proedu is not a palindrome.