C#隐式类型

隐式类型

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace 隐式类型var
{
    class Program
    {
        static void Main(string[] args)
        {
            //优点：不需要在左侧也加上Dictionary<string,string>代码得到简化
            var dict = new Dictionary<string, string>();

            //缺点：从代码上来看不知道具体类型，不容易理解
            var a = 2147483649;
            var b = 928888888888888888;
            var c = 2147483644;
            Console.WriteLine("变量a的类型为:{0}", a.GetType());
            Console.WriteLine("变量b的类型为:{0}", b.GetType());
            Console.WriteLine("变量c的类型为:{0}", c.GetType());
            //隐式类型数组
            var intarray = new[] { 1, 2, 3, 4 };
            var stringarray = new[] { "s", "ad" };

            //匿名类型
            var person = new { Name = "谢峰", Age = "23" };
            Console.WriteLine("{0} 的年龄为：{1}", person.Name, person.Age);

            //定义匿名类型数组
            var personcollection = new[]
                {
                    new {Name="sam",Age=13},
                    new {Name="tom",Age=14},
                    new {Name="jeny",Age=17},
                };
            var totalAge = 0;
            foreach (var p in personcollection)
            {
                totalAge += p.Age;
            }
            Console.WriteLine("所有人的年龄和为：{0}", totalAge);
            Console.Read();

        }
    }
}