CODEWITHSUNDEEP
javastringif-statementfor-loopreturn
suck_at_coding18
suck_at_coding18

Reputation: 41

Finding the index of the first vowel in a string

So i'm having trouble finding the index of the first vowel in a string. This is the code I came up with but its not returning anything. Its supposed to return the index of the first vowel for example if the string was "Hello World" it should return 1 because the index of the first vowel is 'e'. If there is no vowel in the given string it should return -1.

public class Vowel
{
    public static int isVowel(String s)
    {
        int a = -1;
        for(int i = 0; i < s.length(); i++)
        {
            if("aeiouAEIOU".indexOf(i) >= 0)
            {
                a = i;  
            }
        }
        return a;
    }
}

Upvotes: 0

Views: 4835

Answers (3)

Pedro Cerrano
Pedro Cerrano

Reputation: 262

Swift 5.8 I wrote a simple function to find the index of the first vowel in a string:

func findIndexOfFirstVowel(_ word: String) -> Int {
    word.map { $0.lowercased() }.firstIndex(where: { $0 == "a" || $0 == "e" || $0 == "i" || $0 == "o" || $0 == "u" })!
}

I don't recommend force unwrapping in production code, and there may be a more efficient way to check for vowels. Nonetheless, I wanted to offer this as an alternate solution.

Upvotes: 0

gameCoder95
gameCoder95

Reputation: 359

The reason why your method isn't returning anything is because it's checking for the index of an integer within a string of all vowels. What you should do is check the character at i within s, see if it's a vowel, and then return that index.

Also, I would recommend renaming your method to something like "indexFirstVowel". Below is a possible solution if you want to try it:

public class Vowel
{

     public static void main(String[] args)
     {
        int x = indexFirstVowel("Hello World");
     }


     public static int indexFirstVowel(String s)
     {
        for(int i = 0; i < s.length(); i++)
        {
              switch(s.charAt(i))
              {
                  case 'a':
                  case 'e':
                  case 'i':
                  case 'o':
                  case 'u':
                  case 'A':
                  case 'E':
                  case 'I':
                  case 'O':
                  case 'U':
                     return i;
                  default:
                     break;
              }
         }

          return -1;
     }
}

Upvotes: 0

Matthew Diana
Matthew Diana

Reputation: 1106

Utilize a private static method to check if a certain character is a vowel:

public static int firstVowelPos(String s) {
    for (int i = 0; i < s.length(); i++) {
        char c = s.charAt(i);
        if (isVowel(c))
            return s.indexOf(c);
    }
    return -1;
}   

private static boolean isVowel(char c) {
      return "AEIOUaeiou".indexOf(c) != -1;
}

If you don't need to check for vowels anywhere else in your code, this can be simplified by moving the vowel checking into your conditional statement:

public static int firstVowelPos(String s) {
    for (int i = 0; i < s.length(); i++) {
        char c = s.charAt(i);
        if ("AEIOUaeiou".indexOf(c) != -1)
            return s.indexOf(c);
    }
    return -1;
}

Upvotes: 2

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