Java01

import java.util.Scanner;



public class Task01 {

    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        System.out.print("请输入一个double类型的值: ");

        double value = scanner.nextDouble();    

        int intValue = (int) value;

        char charValue = (char) value;

        System.out.println("转换为int: " + intValue);

        System.out.println("转换为char: " + charValue);

    }

}

import java.util.Scanner;



public class Task02 {

    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        System.out.print("请输入圆的半径: ");

        double radius = scanner.nextDouble();

        double circumference = 2 * Math.PI * radius;  

        double area = Math.PI * Math.pow(radius, 2);

        System.out.printf("周长: %.2f\n", circumference);

        System.out.printf("面积: %.2f\n", area);

    }

}

import java.util.Scanner;



public class Task03 {

    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        System.out.print("请输入用户名: ");

        String username = scanner.nextLine();

        System.out.print("请输入密码: ");

        String password = scanner.nextLine();

        String combined = username + "@#" + password;

        System.out.println("拼接结果: " + combined);

    }

}

import java.util.Scanner;



import java.util.Scanner;

public class Task04 {

    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        System.out.print("请输入矩形的长度: ");

        double length = scanner.nextDouble();

        System.out.print("请输入矩形的宽度: ");

        double width = scanner.nextDouble();

        double area = length * width;  // 面积 = 长 × 宽

        System.out.println("矩形面积: " + area);

    }

}

import java.util.Scanner;



public class Task05 {

    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        System.out.print("请输入第一个数字: ");

        double num1 = scanner.nextDouble();

        System.out.print("请输入第二个数字: ");

        double num2 = scanner.nextDouble();

        if (num1 > num2) {

            System.out.println("较大的数: " + num1);

        } else if (num1 < num2) {

            System.out.println("较大的数: " + num2);

        } else {

            System.out.println("两个数相等: " + num1);

        }

    }

}