C#变量引用与全局变量

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

namespace Demo
{
class Program
{
static void ShowDouble(ref int val)
{
val *= 2;
Console.WriteLine("val doubled = {0}", val);
}

static void Main(string[] args)
{
int val = 5;
Console.WriteLine("val = {0}", val); // 5
ShowDouble(ref val); // 同一个内存,10
Console.WriteLine("val = {0}", val); // 10
Console.ReadKey();
}
}
}

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

namespace Demo
{

class Program
{
static int val;
static void ShowDouble()
{
val *= 2;
Console.WriteLine("val doubled = {0}",val);
}

static void Main(string[] args)
{
val = 5;
Console.WriteLine("val = {0}",val); // 5
ShowDouble(); // 同一个内存,10
Console.WriteLine("val = {0}", val); // 10
Console.ReadKey();
}
}
}