2022年6月25日——Java案例（1）

Java练习，第一天，共5个

001——输出语句

package day_01;

public class Demo01 {

    public static void main(String[] args){
        System.out.println("你好，世界！与你相遇是我的荣幸，期待未来的旅途~");
    }
}

002——选择语句-（if，if-else）

package day_01;

import java.util.Scanner;

public class Demo02 {

    public static void main(String[] args){
        System.out.println("根据年龄，判断您当前所处于的时期");
        System.out.print("请输入您的年龄：");
        Scanner sc = new Scanner(System.in);
        int age = sc.nextInt();
        if (age >= 0 && age <= 17){
            System.out.println(age+"岁，您当前属于未成年人");
        }else if (age >= 18 && age <= 65){
            System.out.println(age+"岁，您当前属于青年人");
        }else if (age >= 66 && age <= 79){
            System.out.println(age+"岁，您当前属于中年人");
        }else if (age >= 80 && age <= 99){
            System.out.println(age+"岁，您当前属于老年人");
        }else if (age >= 100){
            System.out.println(age+"您当前属于长寿老人");
        }else {
            System.out.println("您输入的年龄不符合规则");
        }
    }
}

003——循环语句-while

循环语句，除了while之外，还有其它的循环，如：for、do-while等。

package day_01;

import java.util.Scanner;

public class Demo03 {

    public static void main(String[] args){
        System.out.println("小小累加——计算器");
        Scanner sc = new Scanner(System.in);
        boolean flag = true;
        System.out.print("请输入第一个数：");
        double num = sc.nextDouble();
        String title = num + "+";
        double result = num;
        int index = 2;
        while (flag){
            System.out.print("请输入第"+index+"个数（当您输入0即可结束计算）：");
            index++;
            num = sc.nextDouble();
            if (num == 0){
                result += num;
                title+= num;
                System.out.println("结束累加");
                flag = false;
            }else{
                result += num;
                title+= num +"+";
            }
        }
        System.out.println("本次计算的表达式为："+title);
        System.out.println("本次计算的结果为："+result);
    }
}

004——switch

package day_01;

import java.util.Scanner;

public class Demo04 {

    public static void main(String[] args){
        Scanner scanner = new Scanner(System.in);
        System.out.println("时间单位转换器");
        System.out.println("描述：根据您的需要选择相应的功能进行转换");
        System.out.println("1、小时转分钟");
        System.out.println("2、分钟转小时");
        System.out.println("3、天数转分钟");
        System.out.print("请根据您的需要，输入相应的选择：");
        int select = scanner.nextInt();
        switch (select){
            case 1:
                System.out.print("请输入小时数（整数类型）");
                int hour = scanner.nextInt();
                System.out.println(hour+"小时，等于"+(hour*60)+"分钟");
                break;
            case 2:
                System.out.print("请输入分钟数（整数类型）");
                int minute = scanner.nextInt();
                System.out.println(minute+"分钟，约等于"+(minute/60)+"小时");
                break;
            case 3:
                System.out.print("请输入天数（整数类型）");
                int day = scanner.nextInt();
                System.out.println(day+"天，等于"+(day*24*60)+"分钟");
                break;
                default:
                    System.out.println("该功能暂未实现，敬请期待~");
        }
    }
}

005——整合练习1

package day_01;

import java.util.Scanner;

public class Demo05 {

    public static void main(String[] args){
        System.out.println("任务记录册：");
        System.out.println("描述：一周当中每天任务的目标记录");
        Scanner scanner = new Scanner(System.in);
        String result = "";
        for (int i = 0; i < 7; i++) {
            System.out.println("星期"+(i+1)+"，请输入您的目标：");
            String content = scanner.next();
            String str = "";
            switch (i){
                case 0:
                    str = "一";
                    break;
                case 1:
                    str = "二";
                    break;
                case 2:
                    str = "三";
                    break;
                case 3:
                    str = "四";
                    break;
                case 4:
                    str = "五";
                    break;
                case 5:
                    str = "六";
                    break;
                case 6:
                    str = "日";
                    break;
            }
            result+="星期"+str+"："+content+"\n";
        }
        System.out.println("您本周的清单为：");
        System.out.println(result);
        System.out.println("期待您的成果，加油！");
    }
}