String类实现s1>s2的比较

/**
		* <code>s1>s2</code>
		* @param  String s
    *         The initial value of the string
    * @return bool
		*/
		int opCmp(String s){
			return std.string.cmp(cast(char[])this.value, cast(char[])s.value);
		}

下面是测试

public static void  main() {     
   String str = new String("The quick brown fox jumped over the lazy dog.");
   String s1 = new String("abc");
   s1="abc";
   String s2=new String("ab");
   
   writef("s1=");   
   writefln(s1);
   writef("s2=");   
   writefln(s2);
   
   if(s1>s2)
   	printf("s1>s2=%.*s\n","true");
   else
   	printf("s1>s2=%.*s\n","false");
   String s3=new String("ab");
   String s4=new String("abc");
   
   writef("s3=");   
   writefln(s3);
   writef("s4=");   
   writefln(s4);
   if(s3>s4)
   	printf("s3>s4=%.*s\n","true");
   else
   	printf("s3>s4=%.*s\n","false");
      
   printf("%d\n",str.indexOf("z"));
   printf("%d\n",str.isEmpty());
}