D语言核心语言字符串

import std.stdio;

void main(string[] args) { 
   string greeting1 = "Hello all"; 
   writefln("%s",greeting1);  

   char[] greeting2 = "Good morning".dup; 
   writefln("%s",greeting2);  

   string greeting3 = greeting1; 
   writefln("%s",greeting3); 
}