Java中的初始化程序块
Initializer块用于声明构造函数的公共部分。让我们看一个例子-
示例
import java.io.*; public class Demo{ { System.out.println("The common constructor has been invoked"); } public Demo(){ System.out.println("The default constructor has been invoked"); } public Demo(int x){ System.out.println("The parametrized constructor has been invoked"); } public static void main(String arr[]){ Demo my_obj_1, my_obj_2; System.out.println("Demo对象已创建。"); my_obj_1 = new Demo(); my_obj_2 = new Demo(89); } }
输出结果
Demo对象已创建。 The common constructor has been invoked The default constructor has been invoked The common constructor has been invoked The parametrized constructor has been invoked
名为Demo的类包含一个不带参数的构造函数,一个参数化的构造函数和main函数。在主函数内部,创建了Demo类的一个实例,一个实例带参数,一个实例不带参数。