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。