Basic Java: Error: Class, Interface, or Enum Expected

Question

I am trying to write a method to see if the string is a palindrome (Words that can be spelled correctly backwards too, for example "racecar". I cant find the error so maybe another set of eyes will help. Here is the code:

public boolean isPalindrome(String str){
  numberofQuestions++;
  int n = str.length();
  for( int i = 0; i < n/2; i++ )
  if (str.charAt(i) != str.charAt(n-i-1)) return false;
  return true;
}

EDIT: Screenshot of errors:

enter image description here

Start of class:

public class Geek{
private String name;
private int numberofQuestions=0;

Final Edit: Found an extra "{" inside one of the methods. Thanks to everyone for your help!

What's the purpose of `numberofQuestions++`?! #HighlyCurious — Rahul, Nov 01 '13 at 04:24
There is no apparent error. Try looking at the stack trace and finding what piece of code has the error. — Justin, Nov 01 '13 at 04:24
R.J, that is a counter to keep track of the number of questions used in the menu. — user2943817, Nov 01 '13 at 04:26
A good IDE would have allowed you to format the code and avoided the question — Reimeus, Nov 01 '13 at 04:37

Eng.Fouad · Answer 1 · 2016-01-16T17:25:03.890

9

I bet it is something related to missing braces, or braces that closes the class body before starting this method definition.

edited Jan 16 '16 at 17:25

answered Nov 01 '13 at 04:31

Eng.Fouad

115,165
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you win the bet. perfect. Thanks – Syeda Zunaira Jan 16 '16 at 15:53
you win the bet. perfect. Thanks – Syeda Zunaira Jan 16 '16 at 15:54
I can't believe this useless answer is the accepted one after all these years. – Daniel Vukasovich Feb 22 '18 at 13:02

Reimeus · Answer 2 · 2013-11-01T04:34:35.217

2

The method should be fully enclosed within a class

public class Geek {
    private String name;
    private int numberofQuestions = 0;

        public boolean isPalindrome(String str) {
            numberofQuestions++;
            int n = str.length();
            for (int i = 0; i < n / 2; i++)
                if (str.charAt(i) != str.charAt(n - i - 1))
                    return false;
            return true;
        }
    }

edited Nov 01 '13 at 04:34

answered Nov 01 '13 at 04:24

Reimeus

158,255
15
216
276

2

This would fail because `numberofQuestions` is not initialized. – Justin Nov 01 '13 at 04:25
@Quincunx Only local variables need to be initialized. Fields have the default value if not explicitly initialized. – Eng.Fouad Nov 01 '13 at 04:26
@Quincunx numberofQuestions will be initialized with 0 automatically because its a class variable – SpringLearner Nov 01 '13 at 04:27
Beginning of class posted – user2943817 Nov 01 '13 at 04:29
1

@user2943817 Then please post the class so we can see it – Reimeus Nov 01 '13 at 04:30
And always use braces. – MC Emperor Apr 03 '19 at 07:20

score 0 · Answer 3 · edited Nov 01 '13 at 04:36

Make the isPalindrome() function static.

Here's a sample:

public class Sample {

    private static int numberofQuestions;

    public static void main(String[] args)
    {
        String str = "racecar";
        String str2 = "notpalindrome";
        boolean test = isPalindrome(str);
        boolean test2 = isPalindrome(str2);
        System.out.println(str + ": " + test);
        System.out.println(str2 + ": " + test2);
    }

    public static boolean isPalindrome(String str) {
        numberofQuestions++;
        int n = str.length();
        for (int i = 0; i < n / 2; i++)
            if (str.charAt(i) != str.charAt(n - i - 1))
                return false;
        return true;
    }
}

Output:

racecar: true
notpalindrome: false

score 0 · Answer 4 · answered Nov 01 '13 at 04:34

0

You must check your curly braces that whether it is properly ended after looping , method and class.

answered Nov 01 '13 at 04:34

user2885596

59
4

score 0 · Answer 5 · answered Nov 01 '13 at 05:09

I think there is problem in curly braces. You didnt end the bracket of main class Geek{ }.

Check this:

  public class Geek 
   {
        private String name;
        private int numberofQuestions = 0;

            public boolean isPalindrome(String str) 
            {
                numberofQuestions++;
                int n = str.length();
                for (int i = 0; i < n / 2; i++)
                    if (str.charAt(i) != str.charAt(n - i - 1))
                        return false;
                return true;
            }
   }

Basic Java: Error: Class, Interface, or Enum Expected

5 Answers5