Introduction to Java Programming编程题9.6<统计字符串中字母的个数>

/*Enter a string: Joe going out, 78011 characters. */import java.util.Scanner;public class CountLetter {    public static void main(String[] args) {       Scanner input = new Scanner(System.in);        System.out.print("Enter a string: ");        String str = input.nextLine();        int totalLetter = countsLetter(str);        System.out.println(totalLetter + " characters.");    }    public static int countsLetter(String s) {        int count = 0;         for (int i = 0; i < s.length(); i++) {             if (Character.isLetter(s.charAt(i)))                 count++;         }        return count;    }}