为什么在数组名称后加括号和点而不是括号? [英] Why are there parentheses and dots after an array's name instead of brackets?

问题描述

访问数组中的元素时，方括号的用法如下:

When accessing an element in an array the square brackets are used like so:

{'X is an int and Numbers is an int array'}
X := Numbers[8];

但是，在阅读其他人的代码时，有时会发现以下语法:

However, While reading others' code I sometimes find the following syntax:

{'PBox , SBox1 , SBox2 are arrays of int , And X,Y are ints'}
Result := Result or PBox(.SBox1[X] or SBox2[Y].);

1. 如 PBox(someNumber)中那样，在数组名称后加括号是什么意思?这是访问数组元素的另一种方法吗?
2. "是什么?在SBox1之前和之后SBox2是什么意思?SBox1和SBox2都是数组.代码编译没有错误，但我不知道这些点是什么意思.

1. What does it mean to have parentheses after the array's name, as in PBox(someNumber)? Is this another way to access an array element?
2. What does the "." before SBox1 and after SBox2 mean? Both SBox1 and SBox2 are arrays. The code compiles without error but I don't know what those dots are for.

推荐答案

是的，现在我知道您的工作了.

Yes, now I see what you do.

实际上，(.和.)只是编写 [和]的替代方法(但非常罕见！).在Delphi中.

In fact, (. and .) are merely alternative ways (but very uncommon!) of writing [ and ] in Delphi.

如果 PBox 是一个数组，则 PBox [a] (或等效地， PBox(.a.))将需要 a 是整数，对不对?如果 SBox1 [x] 和 SBox2 [Y] 是整数，则按位的或也是整数.(按位 or 是一个接受两个整数并返回新整数的操作.)因此， PBox(.SBox1 [X]或SBox2 [Y].)是<代码>(SBox1 [X]或SBox2 [Y])数组 PBox 中的元素，即整数.因此，计算出 Result 与该整数之间的按位或是有意义的，这是完成的操作:

If PBox is an array, then PBox[a] (or, equivalently, PBox(.a.)) would require a to be an integer, right? And if SBox1[x] and SBox2[Y] are integers, so is the bitwise or of them. (Bitwise or is an operation that takes two integers and returns a new integer.) Hence, PBox(.SBox1[X] or SBox2[Y].) is the (SBox1[X] or SBox2[Y])th element in the array PBox, that is, an integer. So it makes sense to compute the bitwise or between Result and this integer, which is what is done:

Result := Result or PBox(.SBox1[X] or SBox2[Y].);

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