使用类名创建实例变量在Main方法[duplicate]中不起作用

Question

我的意思是当我使用“字符串”，“int”等关键字创建一个istance变量时。我能想象出那个变量。但当我使用类名创建实例变量时，我无法在脑海中想象任何东西。

谢谢你的关心

Answer 1

对于您的第二个问题，在C#中，类的实例总是一个引用变量。（推荐大家上网多看）。因此，在示例中：

class Student
{
   Student st1;
}

str1可以引用RAM中的区域。您可以将它描绘成指向矩形的箭头。箭头是引用矩形的变量，矩形是RAM上的位置。通过在类本身内部创建一个类的实例，我们实际上创建了一个指向一个新矩形的箭头，这个新矩形也有一个可以引用一个矩形的箭头，以此类推。

例如，创建一个节点列表是很有用的。每个节点引用另一个节点,如下所示：

class Node
{
   public int number;
   public Node next; // Here we create a new arrow to a new rectangle, which has an arrow too
}

Node first = new Node();
first.number = 1;

Node second = new Node();
second.number = 2;

first.next = second; // Here we "match" the arrow to a rectangle. The arrow is "first.next", and the rectangle is "second".

Node third = new Node();
third.number = 3;

second.next = third;

// We have a list: 1 -> 2 -> 3 -> null
// The end of the list is null, becuase third.next references to null (it references to no "rectangle")

Node first = new Node();
first.number = 1;

first.next = new Node();
first.next.number = 2;

first.next.next = new Node();
first.next.next.number = 3;

// In this way, we have only the "head" of the list ("first"), but we can get any node that in the list by typing "first.next. ....... .next"

// We can also iterate over the list:
Node p = first;
while (p != null) // while we are not in the end of the list
{
   // Do something, like "Console.WriteLine(p.number);" or "p.number++;"
   p = p.next; // We go to the next node
}

例如：

public class Program
{
     public static void Main(string[] args)
     {
          Node first = new Node();
          int counter = 0;
         
          first.number = counter;
          counter++;
         
          // Inialize a list of 10 nodes:
          Node p = first; // We don't want to lost the "head" of our list, "first"
          while (counter < 10)
          {                
              p.next = new Node(); // We create a new node
              p.next.number = counter; // And we initialize it
              
              counter++;
              p = p.next; // We go to the next node
          }
          
          // Now we print all the number in our list:
          p = first; // We don't want to lost the "head" of our list, "first"
          while (p != null)
          {
              Console.WriteLine(p.number);
              p = p.next; // We go to the next node
          }
     }
}

输出：

0
1
2
3
4
5
6
7
8
9

希望对您有所帮助！