001：C# 中 get set 简写存在的陷阱

Posted 2020-08-08 虽洪水翻腾，我坚定仰望祢

如下代码：

 1 public class Age
 2     {
 3 
 4         private int ageNum ;
 5 
 6         public int AgeNum { 
 7             get{ 
 8                 return this.ageNum;
 9             }
10 
11             set{
12                 this.ageNum = value;
13             }
14         }
15 
16         public int getAgeNum(){
17             return ageNum;
18         }
19 
20         public void setAgeNum(int age){
21             this.ageNum = age;
22         }
23 
24     }

 

在Main中做如下操作：

1     Age age = new Age ();
2     age.setAgeNum (234);
3     Console.WriteLine ("age=" + age.AgeNum);
4 
5     age.AgeNum = 122;
6     Console.WriteLine ("age=" + age.getAgeNum());

输出： 

age=234
age=122

 

 

但如果将 set get 采用简写方式，代码如下

public class Age
    {

        private int ageNum ;

        public int AgeNum { set; get;
        }

        public int getAgeNum(){
            return ageNum;
        }

        public void setAgeNum(int age){
            this.ageNum = age;
        }

    }

Main中内容不变，得到如下结果

age=0
age=234

 

如果修改Main中代码顺序如下

1 age.AgeNum = 122;
2 Console.WriteLine ("age=" + age.getAgeNum());
3 
4 age.setAgeNum (234);
5 Console.WriteLine ("age=" + age.AgeNum);

结果为

age=0
age=122