I am new here. I would be grateful for some help, I am trying to write a program to find the palindromes in a sentence, this is what i have so far. However, whenever I execute it, the palindrome count comes to zero and System.out.println in the for and ifs do not take place, I cannot understand what is wrong. we have to use for loop, and not while.
import java.util.Scanner;
class palcheck {
public void main() {
Scanner sc = new Scanner(System.in);
System.out.println("Enter the sentence please...");// input sentece
String s = sc.next();// the sentence
String wordback = ""; //reverse of a word of the sentence
int count = 0; // palindrome count
String word = "";// for a word of the sentence
int a; // counter
String s2 = null; //sentence but with removed full stop
if (s.charAt(s.length() - 1) == '.')// checking if ends with fullstop
{
s2 = s.substring(0, (s.length() - 1));
}// sentence without fullstop
System.out.println(s2);
String s3 = " " + s2 + " ";
System.out.println(s3);// added a space;
for (int c = 0; c < s3.length(); c++) {
char isspace = s3.charAt(c);
if (isspace == ' ')// checking
{
char x = ' ';// initilaizing
for (a = s3.indexOf(isspace); x != ' '; a++) {
x = s3.charAt(a); //collecting letters for word
word = word + x; // forming word
System.out.println("word is " + word);// the formed word
}
int l2 = word.length();
for (int i = l2 - 1; i >= 0; i--) {
wordback = wordback + word.charAt(i);// forming reverse word
System.out.println("reverse word is " + wordback);
if (word.equalsIgnoreCase(wordback)) {
count = count + 1;
}// increasing palindrome count
word = null;// resetting value
wordback = null;//resetting value
}
}
}
System.out.println("the no of palindromes is " + count);
}
}
Edit: I have tried to change the names of the variables:
import java.util.Scanner;
class palcheck {
public void main() {
Scanner sc = new Scanner(System.in);
System.out.println("Enter the sentence please...");// input sentece
String sentence = sc.next();// the sentence
String wordreverse = ""; //reverse of a word of the sentence
int count = 0; // palindrome count
String word = "";// for a word of the sentence
int a; // counter
String sentencewithoutfullstop = null; //sentence but with removed full stop
if (sentence.charAt(sentence.length() - 1) == '.')// checking if ends with fullstop
{
sentencewithoutfullstop = sentence.substring(0, (sentence.length() - 1));
}// sentence without fullstop
System.out.println(sentencewithoutfullstop);
String sentencewithspace = " " + sentencewithoutfullstop + " ";
System.out.println(sentencewithspace);// added a space;
for (int c = 0; c < sentencewithspace.length(); c++) {
char isspace = sentencewithspace.charAt(c);
if (isspace == ' ')// checking
{
char letter = ' ';// initilaizing
for (a = sentencewithspace.indexOf(isspace); letter != ' '; a++) {
letter = sentencewithspace.charAt(a); //collecting letters for word
word = word + letter; // forming word
System.out.println("word is " + word);// the formed word
}
int length2 = word.length();
for (int i = length2 - 1; i >= 0; i--) {
wordreverse = wordreverse + word.charAt(i);// forming reverse word
System.out.println("reverse word is " + wordreverse);
if (word.equalsIgnoreCase(wordreverse)) {
count = count + 1;
}// increasing palindrome count
word = null;// resetting value
wordreverse = null;//resetting value
}
}
}
System.out.println("the no of palindromes is " + count);
}
}
EDIT: I have redone the program, but its not getting executed. I am using bluej and whenever i am selected void(main), the java virtual machine keeps running and i have to finally terminate it.
Is there a problem in the program?
import java.util.Scanner;
class cal {
public static void main(String args[]) {
Scanner sc = new Scanner(System.in);
String input = sc.next();
String word = null;
String reverse = null;
int count = 0;
if (input.endsWith(".")) {
String Sent2 = input.substring(0, (input.length() - 1));
String sent3 = " " + Sent2 + " ";
int l = sent3.length();
for (int i = 0; i < l; i++) {
if (sent3.charAt(i) == ' ') {
while (sent3.charAt(i + 1) != ' ') {
char h = sent3.charAt(i + 1);
word = word + h;
int l2 = word.length();
for (int j = l2 - 1; j >= 0; j--) {
char hg = word.charAt(j);
reverse = reverse + hg;
if (word.equalsIgnoreCase(reverse)) {
System.out.println("palindrome :" + word);
count++;
}
}
}
}
}
} else {
String sent3 = " " + input + " ";
int l = sent3.length();
for (int i = 0; i < l; i++) {
if (sent3.charAt(i) == ' ') {
while (sent3.charAt(i + 1) != ' ') {
char h = sent3.charAt(i + 1);
word = word + h;
int l2 = word.length();
for (int j = l2 - 1; j >= 0; j--) {
char hg = word.charAt(j);
reverse = reverse + hg;
if (word.equalsIgnoreCase(reverse)) {
System.out.println("palindrome :" + word);
count++;
}
}
}
}
}
}
}
}
This code assumes you have an input String and finds the palindromes inside it.
String word = "";
String inverse = "";
for (int index = 0; index < input.length(); index++) {
if (input.charAt(index) == " ") {
if ((word.length() > 0) && (word.equals(inverse))) {
System.out.println("Palindrome: " + word);
}
word = "";
inverse = "";
} else {
char current = input.charAt(index);
word += current;
inverse = current + inverse;
}
}
if ((word.length() > 0) && (word.equals(inverse))) {
System.out.println("Palindrome: " + word);
}