Changing a string to a Char array

Question

Once a value is stored as a String, how can you loop through string and assign each value to a char array? The occurrences of every vowel in array must also be counted.

This is my current code:

public class Part1_5 {

  /**
   * Method that gets user name and stores it as a string. Each value then
   * assign to a char array. no of vowels are counted and no of each printed
   */
  public static void main(String[] args) {

    // Setting up scanner
    Scanner scanner = new Scanner(System.in);

    // declaring string for name
    String userName = null;

    // declaring ints to hold total no of each vowel
    int totalOfA = 0;
    int totalOfE = 0;
    int totalofI = 0;
    int totalofO = 0;
    int totalofU = 0;

    // Get user input for name
    System.out.println("Please enter your Name...");
    userName = scanner.nextLine();

    for (int loop = 0; loop < userName.length(); loop++) {

      // declaring char array
      char[] letter = userName.toCharArray();

      if (userName.charAt(0) == 'a') {

        totalOfA++;

      }

    }

    System.out.println(totalOfA);

  }

}

Answer 1

String str = "stackoveflow";
char[] aa= str.toCharArray();

And to directly get a char from string, you can use:

str.charAt(i);