第六章第二十题（计算一个字符串中字母的个数）(Count the letters in a string) - 编程练习题答案

import java.util.Scanner;

public class Ans6_20_page201 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("Enter : ");
        String s = input.nextLine();
        System.out.println("The number of letters is "+ countLetters(s));
    }
    public static int countLetters(String s) {
        int count = 0;
        for (int i = 0;i < s.length();i++) {
            if (Character.isLetter(s.charAt(i)))
                count++;
        }
        return count;
    }
}