replace vowel with underscore using array of character

import java.io.*;
public class NewClass
{
    public static void main(String args[])throws IOException
    {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        char word[] = new char[20];
        int index1;

        System.out.print("Enter a word: ");
        reader.read(word, 0, word.length); // array of char , starting offset, array length
        for(index1 = 0; index1 < word.length; index1++)
        {
            if(word[index1]=='a' || word[index1]=='e' || word[index1]=='i' ||
                    word[index1]=='o' || word[index1]=='u')
            {
                word[index1]='_';
            }
        }
        System.out.println(word);
    }
}