public class Person
{
public int age;
public string name;
}
class TestPerson
{
static void Main()
{
Person person = new Person();
Console.WriteLine("Name: {0}, Age: {1}", person.name, person.age);
// Keep the console window open in debug mode.
Console.WriteLine("Press any key to exit.");
Console.ReadKey();
}
}
输出：
Name: , Age: 0
注意，age 的默认值为 0，name 的默认值为 null。有关默认值的更多信息，请参见 默认值表（C# 参考）。
示例 3
下面的示例说明使用基类初始值设定项。 Circle 类是从通用类 Shape 派生的，Cylinder 类是从 Circle 类派生的。每个派生类的构造函数都使用其基类的初始值设定项。
abstract class Shape
{
public const double pi = Math.PI;
protected double x, y;
public Shape(double x, double y)
{
this.x = x;
this.y = y;
}
public abstract double Area();
}
class Circle : Shape
{
public Circle(double radius)
: base(radius, 0)
{
}
public override double Area()
{
return pi * x * x;
}
}
class Cylinder : Circle
{
public Cylinder(double radius, double height)
: base(radius)
{
y = height;
}
public override double Area()
{
return (2 * base.Area()) + (2 * pi * x * y);
}
}
class TestShapes
{
static void Main()
{
double radius = 2.5;
double height = 3.0;
Circle ring = new Circle(radius);
Cylinder tube = new Cylinder(radius, height);
Console.WriteLine("Area of the circle = {0:F2}", ring.Area());
Console.WriteLine("Area of the cylinder = {0:F2}", tube.Area());
// Keep the console window open in debug mode.
Console.WriteLine("Press any key to exit.");
Console.ReadKey();
}
}
输出：
Area of the circle = 19.63
Area of the cylinder = 86.39
注：相关教程知识阅读请移步到c#教程频道。
