reverse a string and checking weather it is palindrome r not

I am working on different things .. here comes i want to print the string reversed output and parallel y check weather it is palindrome or not . .

Note : i enter the string dynamically i.e in console window ..

Help it :)

I can code this scenario in c# at ease but interestingly i an finding too many errors while doing the same . so help it guys

In console window i enter the string like this ::: --> A man a plan , a canal - panama

Ty guys

Try this:

import java.io.*;

class Strings

{

public static void main(String[] args) throws IOException

{

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

String text;

while(true)

{

System.out.println("Enter a line of text or q to quit");

try

{

text = br.readLine();

}

catch(IOException e)

{

System.out.println("Something went wrong, program terminating.");

return;

}

if (text.toLowerCase().equals("q")) return;

char[] chars = text.toCharArray();

// reverse the string

for (int i = text.length() - 1; i >= 0; i--)

{

chars[text.length() - 1 - i] = text.charAt(i);

}

String reverse = new String(chars);

System.out.println(reverse);

Convert to lower case and strip out any non-letters

to see if it's a palindrome or not

char[] letters = new char[text.length()];

int j = 0;

text = text.toLowerCase();

for (int i = 0; i < text.length(); i++)

{

char c = text.charAt(i);

if (c >= 97 && c <= 122) // it's a letter

{

letters[j] = c;

j++;

}

text = new String(letters);

char[] revLetters = new char[reverse.length()];

j = 0;

reverse = reverse.toLowerCase();

for (int i = 0; i < reverse.length(); i++)

{

char c = reverse.charAt(i);

if (c >= 97 && c <= 122) // it's a letter

{

revLetters[j] = c;

j++;

}

reverse = new String(revLetters);

if (text.equals(reverse))

{

System.out.println("It's a palindrome!");

}

else

{

System.out.println("It's not a palindrome");

}

System.out.println();

}

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes13y ago
Accepted answer
Try this:

import java.io.*;

class Strings
{
public static void main(String[] args) throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String text;

while(true)
{
System.out.println("Enter a line of text or q to quit");

try
{
text = br.readLine();
}
catch(IOException e)
{
System.out.println("Something went wrong, program terminating.");
return;
}

if (text.toLowerCase().equals("q")) return;

char[] chars = text.toCharArray();

// reverse the string

for (int i = text.length() - 1; i >= 0; i--)
{
chars[text.length() - 1 - i] = text.charAt(i);
}

String reverse = new String(chars);
System.out.println(reverse);

/*
Convert to lower case and strip out any non-letters
to see if it's a palindrome or not
*/

char[] letters = new char[text.length()];
int j = 0;
text = text.toLowerCase();
for (int i = 0; i < text.length(); i++)
{
char c = text.charAt(i);
if (c >= 97 && c <= 122) // it's a letter
{
letters[j] = c;
j++;
}
}
text = new String(letters);

char[] revLetters = new char[reverse.length()];
j = 0;
reverse = reverse.toLowerCase();
for (int i = 0; i < reverse.length(); i++)
{
char c = reverse.charAt(i);
if (c >= 97 && c <= 122) // it's a letter
{
revLetters[j] = c;
j++;
}
}
reverse = new String(revLetters);

if (text.equals(reverse))
{
System.out.println("It's a palindrome!");
}
else
{
System.out.println("It's not a palindrome");
}

System.out.println();
}
}
}
0
Jaganathan Bantheswaran13y ago
Please change the Topic from java to C#.

string input = "hello world";
string output = new string(input.ToCharArray().Reverse().ToArray());

Console.write("Is " + input + " palindrome? => " + String.Compare(input.Trim(), output.Trim(), true) == 0)
0