C#控制台基础 console.writeline中写加号为何能连接多个字符串之string.concat

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace ConsoleApplication3
 8 {
 9     class Program
10     {
11         static void Main(string[] args)
12         {
13             int num1 = 10;
14             int num2 = 10;
15             double num3 = 10.1;
16 
17             Console.WriteLine(num1.ToString()+num2.ToString()+num3.ToString());
18             Console.ReadKey();
19         }
20     }
21 }