Thread: Vowel frequency in a string, it compiles but getting error

import java.util.Scanner;
public class program4f_4
{
    public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter a string to see how many times each vowel occurs.");
        String message = sc.nextLine();
        message = message.toLowerCase();
        int length = message.length();
        vowelFrequency(message, length);
 
    }
 
    static public void vowelFrequency(String message, int length)
    {
        int vowelA=0;
        int vowelE=0;
        int vowelI=0;
        int vowelO=0;
        int vowelU=0;
        int x = 0;
        char vowel;
 
        for(x = 0; x <= length; x++)
        {
 
            vowel = message.charAt(x);
            if (vowel == 'a')
                vowelA++;
            if (vowel == 'e')
                vowelE++;
            if (vowel == 'i')
                vowelI++;
            if (vowel == 'o')
                vowelO++;
            if (vowel == 'u')
                vowelU++;
 
        }
        System.out.println("Vowel       Occurances");
        System.out.println("A:    " + vowelA);
        System.out.println("E:    " + vowelE);
        System.out.println("I:    " + vowelI);
        System.out.println("O:    " + vowelO);
        System.out.println("U:    " + vowelU);
 
    }
 
}

When I run it it highlights "vowel = message.charAt(x);" and the error message is
"java.lang.StringIndexOutofBoundsException:
String index out of range: 10 (in java.lang.String)". I'm thinking it has something to do with char variable type?

Thanks a lot.