Java目录-编程示例

欢迎来到Java目录-编程示例！这是一个为Java程序员提供的示例代码集合，旨在帮助您快速入门和提升Java编程技能。下面是一些常见的Java编程示例，它们覆盖了各种主题和应用场景。

基本语法和数据类型

Hello World

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}

变量和常量

int a = 10; // 变量
final int MAX_VALUE = 100; // 常量

条件语句

int num = 5;
if (num > 0) {
    System.out.println("正数");
} else if (num < 0) {
    System.out.println("负数");
} else {
    System.out.println("零");
}

循环语句

for (int i = 0; i < 5; i++) {
    System.out.println(i);
}

int i = 0;
while (i < 5) {
    System.out.println(i);
    i++;
}

int j = 0;
do {
    System.out.println(j);
    j++;
} while (j < 5);

数组

int[] numbers = {1, 2, 3, 4, 5};
for (int number : numbers) {
    System.out.println(number);
}

面向对象编程

类和对象

public class Person {
    private String name;
    private int age;
    
    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }
    
    public void sayHello() {
        System.out.println("Hello, my name is " + name);
    }
}

Person person = new Person("Alice", 25);
person.sayHello();

继承

public class Student extends Person {
    private String school;
    
    public Student(String name, int age, String school) {
        super(name, age);
        this.school = school;
    }
    
    public void study() {
        System.out.println("I am studying at " + school);
    }
}

Student student = new Student("Bob", 20, "XYZ University");
student.sayHello();
student.study();

接口

public interface Drawable {
    void draw();
}

public class Circle implements Drawable {
    public void draw() {
        System.out.println("Drawing a circle");
    }
}

Circle circle = new Circle();
circle.draw();

异常处理

try {
    int result = divide(10, 0);
    System.out.println(result);
} catch (ArithmeticException e) {
    System.out.println("除数不能为零");
}

public int divide(int dividend, int divisor) throws ArithmeticException {
    if (divisor == 0) {
        throw new ArithmeticException("除数不能为零");
    }
    return dividend / divisor;
}

输入和输出

控制台输入

import java.util.Scanner;

Scanner scanner = new Scanner(System.in);
System.out.print("请输入一个整数：");
int number = scanner.nextInt();
System.out.println("您输入的整数是：" + number);

文件操作

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

File file = new File("example.txt");
try (FileWriter writer = new FileWriter(file)) {
    writer.write("Hello, World!");
} catch (IOException e) {
    e.printStackTrace();
}

以上只是一些Java编程示例的概览，希望能给您提供一些参考和启发。您可以根据自己的需求进一步学习和开发更复杂的Java应用程序。祝您编程愉快！