StringBuilder做函数参数

static void Main(string[] args)
{
StringBuilder sb = new StringBuilder();
Hello(sb);//StringBuilder做为方法参数使用时不需要赋值,其使用相当于 out str
Console.WriteLine(sb.ToString());
string str;
World(out str);
Console.WriteLine(str);
Console.ReadKey();
}

public static void Hello(StringBuilder sb)
{
sb.Append("StringBuilder Hello World");
}

public static void World(out string str)
{
str = "string Hello World";
}