CODEWITHSUNDEEP
java
J.Cole
J.Cole

Reputation: 29

Don't know how to fix this error, trying to write a method but keep getting the same error

I'm trying to write a method where it will return an integer value of where the first vowel is located in the string "w". I've already created the fist method to find if there is a vowel at a certain location, but when I tried using that method in the new method it says "cannot find symbol - method isVowel()." Does anyone know why this is and how to fix it? I've been told already that I must use the method isVowel in the new method. The error highlights the term "isVowel()" that is used in the last method.

public class words
    {
        private String w;

        /**
         * Default Constructor for objects of class words
         */
        public words()
        {
            // initialise instance variables
            w="";
        }

        /**
         * Assignment constructor
         */
        public words(String assignment)
        {
            w=assignment;
        }

        /**
         * Copy constructor
         */
        public words(words two)
        {
            w=two.w;
        }

        /**
         * Pre: 0<=i<length( )
         * returns true if the character at location i is a vowel (‘a’, ‘e’, ‘i', ‘o’, ‘u’ only), false if not
         */
        public boolean isVowel(int i)
        {
            if (w.charAt(i)=='a')  
                return true; 
            else if (w.charAt(i)=='e')
                return true;
            else if (w.charAt(i)=='i')
                return true;
            else if (w.charAt(i)=='o')
                return true;
            else if (w.charAt(i)=='u')
                return true;
            else return false;
        }
        /**
         * determines whether the first vowel in the String is at location 0, 1, 2, or 3 (don’t worry about exceptions)
         */
        private int findFirstVowel()
        {
            return w.indexOf(w.isVowel());
        }

Upvotes: 0

Views: 65

Answers (2)

FredK
FredK

Reputation: 4084

Another possibility is also:

public boolean isVowel(int i) 
{
    char ch = Character.toLowerCase(w.charAt(i));
    switch(ch) {
        case 'a: case'e': case'i': case 'o': case 'u':
            return true;
    }
    return false;
}

Also, 'y' is often a vowel. Your algorithm gives the incorrect number of vowels for words like "system", "syzygy", "why", etc.

Upvotes: 0

Elliott Frisch
Elliott Frisch

Reputation: 201409

You need to iterate the valid indices of w, and then you can use your isVowel(int) method to check. Something like,

private int findFirstVowel()
{
    for (int i = 0; i < w.length(); i++) {
        if (isVowel(i)) {
            return i;
        }
    }
    return -1;
}

Also, you might consider reducing your if-else chain to a basic return in isVowel (and I note you currently only match lower-case letters, but we could also make it case-insensitive). Like,

public boolean isVowel(int i) 
{
    char ch = Character.toLowerCase(w.charAt(i));
    return ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u';
}

Upvotes: 1

Related Questions