class Program
    {
        static void Main(string[] args)
        {
            string name = "小华";
            string speak;
            //调用方法前ref参数必须初始化赋值;
            //调用方法前out参数不用初始化赋值,需要在方法内部赋值;
            var result = show(ref name, out speak);
            Console.WriteLine(result); 
            //总结,ref和out关键字
            //相同:都是引用传递
            //不同：ref有进有出,out只出不进
 
        }

        private static string show(ref string name,out string speak) 
        {      
            speak = "hello";  //out参数,方法内赋值
            return $"{name}说:{speak}";
        }