Java静态成员与方法全解析

public class Person {
    private String name;
    public static int count = 0; // 静态变量
public Person(String name) {
    this.name = name;
    count++; // 每创建一个对象，计数加1
}

public static void showCount() {
    System.out.println("已创建 " + count + " 个Person对象");
}
}

Person p1 = new Person("张三");
Person p2 = new Person("李四");
Person.showCount(); // 输出：已创建 2 个Person对象

public class MathUtils {
    public static int add(int a, int b) {
        return a + b;
    }
public static double circleArea(double radius) {
    return 3.14159 * radius * radius;
}
}

int sum = MathUtils.add(5, 3);
double area = MathUtils.circleArea(2.5);

public class Config {
    public static String APP_NAME;
static {
    APP_NAME = "MyApp";
    System.out.println("静态块执行，初始化配置");
}
}