值类型和引用类型的赋值及深拷贝探究

本文主要讲述的是值类型和引用类型的赋值及深拷贝

对值类型和引用类型的定义以及由来不清晰的可以看我之前的随笔，链接如下：

https://www.cnblogs.com/ShawBlack/p/16997772.html

　　由值类型和引用类型定义得知，值类型变量中存储的是其数据本身，而引用类型中存储的是数据的地址。

　　所以很明显，在我们使用赋值符号时

　　对于引用类型，直接赋值，很明显只是把地址赋值给新的引用类型变量了，使得二者指向的是同一对象。对于引用类型变量的多次赋值，其实也只是多次赋值地址而已。

　　举个栗子：

　　C#：

internal class Program
    {
        static void Main(string[] args)
        {
            WeatherForecast weatherForecast1 = new WeatherForecast() { TemperatureC = 111, Date = Convert.ToDateTime("1111.01.01") };
            WeatherForecast weatherForecast2 = new WeatherForecast() { TemperatureC = 222, Date = Convert.ToDateTime("2222.02.02") };
            //
            WeatherForecast weatherForecast_forCopy = weatherForecast1;  //将weatherForecast1中的地址赋值给weatherForecast_forCopy，使得二者指向同一个对象
            weatherForecast_forCopy.Date = Convert.ToDateTime("3333.03.03");
            weatherForecast_forCopy.TemperatureC = 333;
            Console.WriteLine("weatherForecast1.TemperatureC = " + weatherForecast1.TemperatureC);
            Console.WriteLine("weatherForecast1.Date = " + weatherForecast1.Date.ToLongDateString());
            //
            weatherForecast_forCopy = weatherForecast2;//将weatherForecast2中的地址赋值给weatherForecast_forCopy，使得二者指向同一个对象
            weatherForecast_forCopy.Date = Convert.ToDateTime("4444.04.04");
            weatherForecast_forCopy.TemperatureC = 444;
            Console.WriteLine("weatherForecast1.TemperatureC = " + weatherForecast1.TemperatureC);
            Console.WriteLine("weatherForecast1.Date = " + weatherForecast1.Date.ToLongDateString());
            Console.WriteLine("weatherForecast2.TemperatureC = " + weatherForecast2.TemperatureC);
            Console.WriteLine("weatherForecast2.Date = " + weatherForecast2.Date.ToLongDateString());
        }
    }

    public class WeatherForecast
    {
        public DateTime Date { get; set; }

        public int TemperatureC { get; set; }

        public int TemperatureF => 32 + (int)(TemperatureC / 0.5556);

        public string Summary { get; set; }
    }

　　结果：

　　C++：