传址，ref，out

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

namespace ConsoleApplication1
{
    class Class1
    {
        static void Main(string[] args)
        {
            // 传值
            int i1 = 1, i2 = 2;
            swap(i1, i2);
            Console.WriteLine("{0} {1}", i1, i2);

            // 传址,ref传址之前一定要先赋值
            int i3 = 1, i4 = 2;
            swap(ref i3, ref i4);
            Console.WriteLine("{0} {1}", i3, i4);

            // 传址,out传址之前不用先赋值，即使赋值了也没用，传址以后一定要赋值
            int i5 = 1, i6 = 2;
            swap2(out i5, out i6);
            Console.WriteLine("{0} {1}", i5, i6);

            Console.ReadKey();
        }

        /**
         * 交换数据i1和i2
         */
        static void swap(int i1, int i2)
        {
            int temp;
            temp = i1;
            i1 = i2;
            i2 = temp;
        }

        /**
         * 交换数据i1和i2
         */
        static void swap(ref int i1, ref int i2)
        {
            int temp;
            temp = i1;
            i1 = i2;
            i2 = temp;
        }

        /**
         * 交换数据i1和i2
         */
        static void swap2(out int i1, out int i2)
        {
            // 传址以后一定要赋值
            i1 = 5;
            i2 = 6;

            int temp;
            temp = i1;
            i1 = i2;
            i2 = temp;
        }

    }
}