Java21天打卡-Day15 数组

import java.util.Arrays;

public class Day15 {
    //数组
    //题目1：
    //创建一个长度是8的字符串数组，使用8个长度是5的随机字符串初始化这个数组 对这个数组进行排序，按照每个字符串的首字母排序(无视大小写)
    //注1： 不能使用Arrays.sort() 要自己写
    //注2： 无视大小写，即 Axxxx 和 axxxxx 没有先后顺序

    public static void main(String[] args) {
        String []str = new String[8];
        for(int i =0;i<str.length;i++){
            str[i]= makeStr();
        }
        System.out.println("排序前"+ Arrays.toString(str));

        for (int j = 0; j < str.length; j++) {
            for (int i = 0; i < str.length - j - 1; i++) {
                char firstChar1 = str[i].charAt(0);
                char firstChar2 = str[i + 1].charAt(0);
                firstChar1 = Character.toLowerCase(firstChar1);
                firstChar2 = Character.toLowerCase(firstChar2);

                if (firstChar1 > firstChar2) {
                    String temp = str[i];
                    str[i] = str[i + 1];
                    str[i + 1] = temp;
                }
            }
        }
        System.out.println("排序后"+Arrays.toString(str));
}
    public  static String makeStr(){
        String pool = "";
        for (short i = '0'; i <= '9'; i++) {
            pool+=(char)i;
        }
        for (short i = 'a'; i <= 'z'; i++) {
            pool+=(char)i;
        }
        for (short i = 'A'; i <= 'Z'; i++) {
            pool+=(char)i;
        }
        char cs2[] = new char[5];
        for (int i = 0; i < cs2.length; i++) {
            int index = (int) (Math.random()*pool.length());
            cs2[i] =  pool.charAt( index );
        }
        String result2 = new String(cs2);
        return result2;
    }
}