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Java Palindrome Program

Azhar123Azhar123 Posts: 2Member
Hi! Just started using Java not to long ago and have a question for a program

I'm suppoosed to check to see if an entered String is a palindrome or not..I have created the checking method, but do not know if it is correct. I also have to still create the constructer method. Here is what I have so far:


// Lab16ast.java
// This is the student version of the Lab16a assignment.


import java.io.*;


public class Lab16a
{
public static void main (String args[]) throws IOException
{
BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter a string ===>> ");
Palindrome p=new Palindrome(input.readLine());
p.displayData();


}
}


class Palindrome
{
private String s;
private boolean palindrome;

private boolean isPal()
{

int start = 0;
int end = s.length() - 1;
while (start <= end)
{
if (s.charAt(start) != s.charAt(end))
{
return false;
}
start++;
end--;
}

return true;

}

public Palindrome(String s)
{


}

public void displayData()
{
System.out.println(s);
System.out.println(palindrome);

}


}


Comments

  • zibadianzibadian Posts: 6,349Member
    : Hi! Just started using Java not to long ago and have a question for a program
    :
    : I'm suppoosed to check to see if an entered String is a palindrome or not..I have created the checking method, but do not know if it is correct. I also have to still create the constructer method. Here is what I have so far:
    :
    :
    : // Lab16ast.java
    : // This is the student version of the Lab16a assignment.
    :
    :
    : import java.io.*;
    :
    :
    : public class Lab16a
    : {
    : public static void main (String args[]) throws IOException
    : {
    : BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
    : System.out.println("Enter a string ===>> ");
    : Palindrome p=new Palindrome(input.readLine());
    : p.displayData();
    :
    :
    : }
    : }
    :
    :
    : class Palindrome
    : {
    : private String s;
    : private boolean palindrome;
    :
    : private boolean isPal()
    : {
    :
    : int start = 0;
    : int end = s.length() - 1;
    : while (start <= end)
    : {
    : if (s.charAt(start) != s.charAt(end))
    : {
    : return false;
    : }
    : start++;
    : end--;
    : }
    :
    : return true;
    :
    : }
    :
    : public Palindrome(String s)
    : {
    :
    :
    : }
    :
    : public void displayData()
    : {
    : System.out.println(s);
    : System.out.println(palindrome);
    :
    : }
    :
    :
    : }
    :
    :
    :
    Although this is not really the right board for Java (Java and Javascript are two completely different languages) and I am not a Java programmer, I might see a problem in the isPal() method. The return value might always be true, if Java does not break out the method upon setting the return value to false.
  • chiProgrammerchiProgrammer Posts: 14Member
    Hey try this
    [code]
    import java.io.*;
    public class Palindrome
    {
    private String palin;
    public Palindrome()
    {
    palin = "";
    }
    public Palindrome(String str)
    {
    palin = str;
    }
    public static boolean testPalindrome(String s)
    {
    String a = s.toLowerCase( );
    String b = "";
    for (int x = 0; x < a.length ( ); x++)
    {
    char c = a.charAt(x);
    if (c >='a' && c <= 'z')
    {
    b += c;
    }
    }
    String d = "";
    for (int y = b.length()-1; y >= 0; y--)
    {
    d += b.charAt(y);
    }
    return (b.equals(d));
    }

    public static void main(String []args)
    throws IOException
    {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    System.out.println(" Welcome to the Palindrome Tester!!!
    Enter a word Phrase or String
    Press q or type quit to stop the program at anytime");
    String ing = "";
    do{
    System.out.println("Input?");
    ing = in.readLine();
    if (testPalindrome(ing) == true)
    {
    System.out.println(" "+ing+" is a palindrome");
    }
    else
    {
    System.out.println(" "+ing+" is not a palindrome");
    }
    }while (!ing.equalsIgnoreCase("q") &&
    !ing.equalsIgnoreCase("quit"));

    }
    }
    [/code]

    : : Hi! Just started using Java not to long ago and have a question for a program
    : :
    : : I'm suppoosed to check to see if an entered String is a palindrome or not..I have created the checking method, but do not know if it is correct. I also have to still create the constructer method. Here is what I have so far:
    : :
    : :
    : : // Lab16ast.java
    : : // This is the student version of the Lab16a assignment.
    : :
    : :
    : : import java.io.*;
    : :
    : :
    : : public class Lab16a
    : : {
    : : public static void main (String args[]) throws IOException
    : : {
    : : BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
    : : System.out.println("Enter a string ===>> ");
    : : Palindrome p=new Palindrome(input.readLine());
    : : p.displayData();
    : :
    : :
    : : }
    : : }
    : :
    : :
    : : class Palindrome
    : : {
    : : private String s;
    : : private boolean palindrome;
    : :
    : : private boolean isPal()
    : : {
    : :
    : : int start = 0;
    : : int end = s.length() - 1;
    : : while (start <= end)
    : : {
    : : if (s.charAt(start) != s.charAt(end))
    : : {
    : : return false;
    : : }
    : : start++;
    : : end--;
    : : }
    : :
    : : return true;
    : :
    : : }
    : :
    : : public Palindrome(String s)
    : : {
    : :
    : :
    : : }
    : :
    : : public void displayData()
    : : {
    : : System.out.println(s);
    : : System.out.println(palindrome);
    : :
    : : }
    : :
    : :
    : : }
    : :
    : :
    : :
    : Although this is not really the right board for Java (Java and Javascript are two completely different languages) and I am not a Java programmer, I might see a problem in the isPal() method. The return value might always be true, if Java does not break out the method upon setting the return value to false.
    :

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