Enter a String from keyboard and check whether it Palindrome or Not

Length():-This method is a predefined method of String class present in java. Lang package. It is used to determine the length of string and return type of this method is int type.

Syntax: public int length()

getBytes():-This method is a predefined method of String class present in java .lang package.It is used to ,convert a String into an array of bytes.

Syntax: public byte[] getBytes()

Algorithm for palindrome or not:-

step 1: Read str

step 2: Set size = str.length()

step 3: Create a byte array reference b[]

step 4: b[] = str getBytes()

step 5: create d byte array b1[] of size

step 6: initialize i=size-1

step 7: repeat through step-10 while (i>=0)

step 8: set x=size-(i+ 1)

step 9: b1[x]=b[i]

step 10: i=i-i

step 11: set count=0

step 12: reset i= 0

step 13: repeat through step-15 while (i < size)

step 14: if (b1[i]==b[i]) then count = count+1

step 15: i=i+ 1

step 16: if count==size then print “string is palindrome”

else print “string is not a palindrome”

step 17: Exit

Here is the Java Example for palindrome or not:

import java.util.Scanner; 
 public class PalindromeorNot 
 { 
                        public static int count=0; 
                        public static void main(String args[]) 
               { 
                        Scanner s=new Scanner(System.in); 
                        System.out.print("Enter the String : "); 
                        String str=s.nextLine(); 
                        int size=str.length(); 
                        byte b[]=str.getBytes(); 
                        byte bl[]=new byte[size]; 
                   for(int i=size-1;i>=0;i--) 
                       { 
                               int x=size-(i+1); 
                               bl[x]=b[i]; 
                        } 
                               for(int i=0;i<size;i++) 
                              { 
                                     if(bl[i]==b[i]) 
                                           { 
                                                 count++; 
                                           } 
                              } 
                                     if(count==size) 
                                          { 
                                                  System.out.println(str+" is a Pallindrome."); 
                                          } 
                                    else 
                                    { 
                                                  System.out.println(str+" is not a pallindrome."); 
                                     } 
               } 
 }