Java中 Character方法練習：字元串中英文字母個數 5435abc54abc3AHJ5

package com.swift;

public class String_Letter_Number_Test {

    public static void main(String[] args) {
        /*
         * 字元串中英文字母個數 5435abc54abc3AHJ5
         */
        String str="5435abc54abc3AHJ5";
        char[] arr=str.toCharArray();
        
        int num=0;
        for(char c:arr) {
            if(Character.isLetter(c)) {
                num++;
            }
        }
        System.out.println("The numbers of letter int the String is :"+num);

    }

}