声明指针类型？ [英] Declaring type of pointers?

问题描述

我刚才读，我们需要指点的类型，而在C（或C ++）即宣布他们：

I just read that we need to give the type of pointers while declaring them in C (or C++) i.e.:

int *point ;

据我所知，存储指针变量的地址，地址占用的内存相同数量的任何可能的类型。
那么，为什么我们需要声明它的类型？

As far as I know, pointers store the address of variables, and address occupies same amount of memory whatever may be the type. So, why do we need to declare its type?

推荐答案

类型安全。如果你不知道什么是 P 应该指向，那么会是什么，以prevent类错误，如

Type-safety. If you don't know what p is supposed to point to, then there'd be nothing to prevent category errors like

*p = "Nonsense";
int i = *p;

静态类型检查是preventing各种错误这样的一个非常强大的工具。

Static type checking is a very powerful tool for preventing all kinds of errors like that.

C和C ++也支持的指针运算的，如果目标类型的大小是已知的才有效。

C and C++ also support pointer arithmetic, which only works if the size of the target type is known.

地址占用的内存量相同不管我是类型

address occupies same amount of memory whatever my be the type

这对当今流行的平台上实现。但已经有平台的量，这是并非如此。例如，一个指针指向一个多字节字可能比一个指向一个字节较小，因为它不需要重新present字节的字内的偏移

That's true for today's popular platforms. But there have been platforms for which that wasn't the case. For example, a pointer to a multi-byte word could be smaller than a pointer to a single byte, since it doesn't need to represent the byte's offset within the word.

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