random 练习

Posted 2021-03-20 lq970811

package com.sk.skkill;

import com.sun.media.jfxmediaimpl.HostUtils;
import org.junit.jupiter.api.Test;

import java.util.*;

public class demo
{

    @Test
    public void xunhuan()
    {
        int num=10;
        while (num<=100){


            System.out.println(num);

            num++;
            if(num%6==0)
            {

                continue;
            }
        }
        System.out.println("统计次数："+(num));

    }

    @Test
    public void character(){
Character character=new Character(‘a‘);
        System.out.println(character);
        System.out.println(character.compareTo(‘a‘));
        System.out.println(character.compareTo(‘b‘));
        System.out.println(character.isLetter(‘1‘));
        System.out.println(character.isUpperCase(‘T‘));

    }

    @Test
    public void str(){
        char []  arr ={‘H‘,‘e‘,‘l‘,‘l‘,‘o‘};
        String zf ="人生苦短，我学python";
        System.out.println(zf);
        System.out.println(arr);
        String string =new String(arr);
        System.out.println(string);
        System.out.println(arr.equals(string));
        System.out.println(zf.substring(3,6));//截取3---6 其实是5
        System.out.println(string.split(",",1));
        System.out.println(string.indexOf("e"));//获取下标1
        System.out.println(string.charAt(1));//获取下标1的值 e
        System.out.println(zf.concat("。。。"+string));//拼接字符串
        System.out.println(zf.contentEquals(string));
        System.out.println(string.toUpperCase());
        char [] rd ={97};
        Arrays.sort(rd);
        System.out.println(rd);

        int num =97;
        for (int i=0;num<122+1;i++){

            Random random=new Random();

            char sjchar = (char)random.nextInt(num);
           int sjint=random.nextInt(num);

            System.out.println("随机后的数字："+sjint);
            System.out.println("随机后转换的字母:"+sjchar);
            System.out.println();
            System.out.println("-----------------
");
            System.out.println(num+"	"+"对应的字母	"+(char) num);
           char charst =(char) num;
           String uppCase = String.valueOf(charst);
            System.out.println(num+"	"+"对应的大写字母	"+uppCase.toUpperCase());
            num++;
        }


    }
    @Test
public void collection()
{
    String array [] ={"明天会更好","为你写诗","宁夏","下一个天亮","梦醒时分","光阴的故事"};
    for(String item:array){
        System.out.println(item);
    }
    List<String> list =new ArrayList<String>();
    for (int i=0;i<array.length;i++){

        list.add(String.valueOf(array[i]) );//数组转换称string


    }
    System.out.println(list);
    System.out.println(list.equals("江南"));
    System.out.println(list.get(2));


}



@Test
    public void whiles(){
        int num =100;
        int nums=0;
int sum= 0;
        while (num>10)
        {
            System.out.println(num);
            num--;
        }
    System.out.println("------------------------");
    while (nums<10)
    {
        nums++;

        sum +=nums;
        System.out.println(sum);

    }

}

}