29、Java 字符串与数组的深入探索

Java 字符串与数组的深入探索

1. StringBuilder 示例与 CharSequence 接口

在 Java 编程中，字符串处理是一项常见任务。为了说明 StringBuilder 类的工作原理，这里有一个 MarkVowels 程序的 StringBuilder 版本：

import java.util.Scanner;
public class StringBuilderApp
{
    static Scanner sc = new Scanner(System.in);
    public static void main(String[] args)
    {
        System.out.print("Enter a string: ");
        String s = sc.nextLine();
        StringBuilder sb = new StringBuilder(s);
        int vowelCount = 0;
        for (int i = 0; i < s.length(); i++)
        {
            char c = s.charAt(i);
            if (    (c == 'A') || (c == 'a')
                 || (c == 'E') || (c == 'e')
                 || (c == 'I') || (c == 'i')