Construction code block:
(1) Function: initializes the object, executes the object as soon as it is created, and takes precedence over the constructor
(2) Differences between building code blocks and constructors:
The construction code block is to initialize the commonness of all different objects, and the constructor is to initialize the corresponding objects
class Cylinder //定义类Cylinder
{
private double radius;
private int height;
private double pi=3.14;
String color;
private Cylinder() //定义私有的构造方法
{
System.out.println("无参构造方法被调用了");
}
public Cylinder(double r, int h, String str) //定义有三个参数的构造方法
{
this(); //在公共构造方法中用this关键字来调用另一构造方法
radius=r;
height=h;
color=str;
}
public void show()
{
System.out.println("圆柱底半径为:"+ radius);
System.out.println("圆柱体的高为:"+ height);
System.out.println("圆柱的颜色为:"+color);
}
double area()
{
return pi* radius* radius;
}
double volume()
{
return area()*height;
}
}
public class Javase_11 //主类
{
public static void main(String[] args)
{
Cylinder volu=new Cylinder(2.5,5,"蓝色");
System.out.println("圆柱底面积="+ volu.area());
System.out.println("圆柱体体积="+volu.volume());
volu.show();
}
}