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Thread: confused

  1. #1
    Junior Member joon's Avatar
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    Default confused

    Hi,
    I'm new to this forum and this is my first post so I hope I'm posting in the correct spot and that I am doing it correctly. I'm really new to programming but very keen to learn. Doing an IT degree. If anyone can tell me what I have done wrong here that would be great.
    The program should count the amount of vowels that are in a string entered by the user.

    import java.util.Scanner;
    public class VowelCounter {
     
     
        public static void main(String[] args) {
            Scanner input = new Scanner(System.in);
     
     
            char vowelCounter[] = new char[5];
            vowelCounter[0] = 'a';
            vowelCounter[1] = 'e';
            vowelCounter[2] = 'i';
            vowelCounter[3] = 'o';
            vowelCounter[4] = 'u';
     
            //Prompt user to input a string
            int counter = 0;
            String aString;
            System.out.println("Enter a string of text: ");
            aString = input.nextLine();
            if (aString == "")
            {
                aString = input.nextLine();
            }
     
            for (int i = 0; i < aString.length(); i++)
            {
                char charInPosition = aString.charAt(i);
     
                for (int j = i+1; j < vowelCounter.length; j++ )
                {
                    if (charInPosition == vowelCounter[j])
                    {
                        counter++;
                    }
     
                }
            }
            System.out.println(counter);
     
     
     
        }
     
    }


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    Default Re: confused

    Compare the contents of objects (e.g. String) with the equals() method, not '=='. In this case you can use aString.isEmpty().

    Your inner loop counter that is checking the current input string character against the vowels should start at 0. It has nothing to do with the outer loop counter 'i'.

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    joon (June 11th, 2011)

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    Junior Member joon's Avatar
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    Default Re: confused

    Thanks very much dlorde. That was an easy fix but It was beyond me.

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    Default Re: confused

    If you don't have a debugger or don't know how to use one, the easiest way to spot what's wrong in code like that is to step through it by hand, with pencil and paper and track the values of variables as you go. With experience, you can spot these sorts of errors just by reading the code, but knowing how to use a debugger is worth its weight in notepads and pencils...

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    joon (June 12th, 2011)

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    Junior Member joon's Avatar
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    Default Re: confused

    Yeh I'm not too sure how to use the debugger but I will have a look online and see if I can find some tutorials. I guess I need a bit more time as well. I've only been learning for three months so I'm not really sure about everything. I have so much work to learn with uni that I don't have time to concentrate on just programming.
    Thanks for the tips and the help though.
    Last edited by joon; June 12th, 2011 at 12:42 PM.

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