【JAVA学习笔记-day1】例题练习

最近在学Java，每天整理一下遇到的例题。

1、用if-else，输入三个数字，从小到大显示。

           Scanner scanner = new Scanner(System.in);
           String s = scanner.nextLine().toString();
           String arr[] = s.split(" ");
           int[] a = new int[3];
           for (int i = 0; i < 3; i++) {
               a[i] = Integer.parseInt(arr[i]);
           }

           if (a[0] > a[1]) {
               if (a[2] > a[0]) {
                   System.out.println(a[1] + "," + a[0] + "," + a[2]);
               } else if (a[2] < a[1]) {
                   System.out.println(a[2] + "," + a[1] + "," + a[0]);
               } else {
                   System.out.println(a[1] + "," + a[2] + "," + a[0]);
               }
           } else {
               if (a[2] > a[1]) {
                   System.out.println(a[0] + "," + a[1] + "," + a[2]);
               } else if (a[2] < a[0]) {
                   System.out.println(a[2] + "," + a[0] + "," + a[1]);
               } else {
                   System.out.println(a[0] + "," + a[2] + "," + a[1]);
               }
           }

2、两个int，判断两个数之和，如果大于50，打印hello world

Scanner scanner=new Scanner(System.in);
        int a=scanner.nextInt();
        int b=scanner.nextInt();
        if (a+b>50)
            System.out.println("hello world");
        else
            System.out.println("两个数之和小于50");

3、声明两个double，判断第一个数字大于10.0，且第二个数小于20.0，打印两数之和，否则，打印乘积。

Scanner scanner=new Scanner(System.in);
        double a=scanner.nextDouble();
        double b=scanner.nextDouble();
        double sum=a+b;
        double multi=a*b;

        if(a>10.0 && b<20.0)
            System.out.println("两个数之和为："+sum);
        else
            System.out.println("两个数乘积为："+multi);

4、计算5岁狗相当于人多少岁？狗的前两年相当于人的10.5岁。之后每增加一年就增加4岁。

Scanner scanner=new Scanner(System.in);
        double a=scanner.nextDouble();
        double b=scanner.nextDouble();
        double sum=a+b;
        double multi=a*b;

        if(a>10.0 && b<20.0)
            System.out.println("两个数之和为："+sum);
        else
            System.out.println("两个数乘积为："+multi);

5、

System.out.println("q请填写大致情况：");
        Scanner scanner=new Scanner(System.in);
        System.out.println("身高：");
        int tall=scanner.nextInt();
        System.out.println("财富：");
        double money=scanner.nextDouble();
        System.out.println("帅么");
        boolean s=scanner.nextBoolean();
       if(tall>180 && money>3 && s){
           System.out.println("一定嫁");
       }else if (tall>180 || money>3 || s){
           System.out.println("凑合");
       }else{
           System.out.println("no");
       }