VowelReplacer and StringRemover

Our task for the last few weeks has been to create a simple program that replaces vowels in a String input with something else (I've chosen the letter "z", because, you know, "zzzz..."). You can find my code below:


import java.util.Scanner; 

class VowelReplacer {
   
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String string = scanner.nextLine();
        char[] vowels = {'a', 'e', 'i', 'o', 'u'};
        for (char c : vowels) {
            // System.out.println("Value of c: " + c);
            string = string.replace(c, 'z');
            // System.out.println(string);
        }
       
        System.out.println(string);
    }
}

And here's a program that removes all occurrences of a user-specified String from a String input:

import java.util.Scanner;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
public class StringRemover {
   
    public static void main(String[] args) {
     Scanner scanner = new Scanner(System.in);
     System.out.println("Please type a word or sentence:");
        String stringToChange = scanner.nextLine();
        Pattern pattern = Pattern.compile(stringToChange);
        System.out.println("Please type a String:");
        String stringToRemove = scanner.nextLine();
        Matcher matcher = pattern.matcher(stringToChange);
       
        if (matcher.find()) {
         stringToChange = stringToChange.replaceAll(stringToRemove, "");
        }
       
        System.out.println("Resulting String is \"" + stringToChange + "\"");
    }
}
Please note that the second of these two programs has one major limitation - it's case-sensitive.