有个小程序:
import std.string;
const MaxListSize = 20; //the max size of the linelist1

struct STU
{
char[10] name;
char[10] stuno;
int age;
int score;
};
alias STU ElemType;
class List //the definition of linelist
{
private:
ElemType[MaxListSize] elem; //to store the elements
int length;//current size
int MaxSize;//max size
public:
//initialize the linelist
this(int ms)
{
length = 0;
MaxSize = ms;
}
//delete the head, tail or one element that equals to e
bool listDelete(int mark, out ElemType e)
{
if(length == 0) return false;
if(mark > 0) //delete the head
{
e = elem[0];
for(int i = 1; i < length; i++)
elem[i - 1] = elem[i];
}
else
{
if(mark < 0)
e = elem[length - 1]; //delete the tail,
else //delete the element which equals to e
{
int i;
for(i = 0; i < length; i++)
if(cmp(elem[i].name, e.name) == 0) break;
if(i == length) return false;
else
{
e = elem[i];
for(int j = i + 1; j < length; j++)
elem[j - 1] = elem[j];
}
}
}
--length;
return true;
}
}
编译出错：test.d(38): Error: array 'length' hides other 'length' name in outer scope
但我怎么也找不出外出作用域有个length

文档里有说,如果后缀表达式 的类型为静态或者动态数组，会隐式地声明变量 length ，并将数组的长度赋给它。
试试这个就知道

void main()
{
	char[] a = "12345";
	char b = a[length-1];
	assert(b == '5');
}

明白了，谢谢tomqyp