C语言中的％d和％p printf格式字符串指令之间的区别? [英] Difference between %d and %p printf format string directives in c language?

问题描述

我想详细了解printing pointer使用%d和%p类型之间的区别.

I want to get a detailed explanation on the difference between using %d and %p type for printing pointer.

也 为什么%p返回十六进制? %d和%p返回不同值的情况是什么? 数据类型仅表示用户想要输出的方式还是与存储位置有关?

Also Why does %p return hexadecimal? What are the cases when %d and %p return different values? Does datatype only represent the way the user wants the output or it has something to do with the memory locations too?

推荐答案

为使程序定义良好，格式说明符必须与参数的类型匹配.因此，您可以使用%p而不是%d来打印指针. (后者可能碰巧适用于某些体系结构，但从技术上讲不确定的行为.)

For the program to be well-defined, the format specifier must match the type of the argument. Therefore you can use %p but not %d to print out pointers. (The latter might happen to work on some architectures but is technically undefined behaviour.)

不能自由交换%d和%p的主要原因是ints和指针不必具有相同的大小.

The primary reason you can't freely interchange %d and %p is that ints and pointers don't have to have the same size.

打印指针的格式是特定于体系结构的(指针可以具有不同的大小，或者甚至可以具有不同的结构).但是，通常以十六进制形式记录内存地址，因此%p通常这样做.

The format in which pointers are printed out is architecture-specific (pointers can have different size or indeed different structure). It is, however, common to transcribe memory addresses in hexadecimal, so this is what %p usually does.

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