blocks|key|2910166|text|p是打印指针的转换说明符。使用这个。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2910167|int+a+=+42;

printf("%25p\n",+(void+*)+&a);|code-block|syntax|javascript|2910168|请记住，省略类型转换是未定义的行为，使用p转换说明符的打印是以实现定义的方式完成的。|2910169|entityMap^0|0|1|0|0|K|1|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

<code>p</code> is the conversion specifier to print pointers. Use this.

<pre><code>int a = 42;

printf("%p\n", (void *) &amp;a);
</code></pre>

Remember that omitting the cast is undefined behavior and that printing with <code>p</code> conversion specifier is done in an implementation-defined manner.

blocks|key|243279|text|使用%25p来表示“指针”，不要使用其他任何*。标准并不保证你可以像对待任何特定类型的整数一样对待指针，所以你实际上会得到整数格式的未定义行为。(例如，%25u需要unsigned+int，但如果void*的大小或对齐要求与unsigned+int不同，该怎么办？)|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|243280|*)看Jonathan的好答案！除了%25p之外，您还可以使用C99中添加的<inttypes.h>中特定于指针的宏。|243281|在C中，所有对象指针都可以隐式转换为void*，但为了将指针作为可变参数传递，您必须显式转换它(因为任意对象指针只能转换，但不等同于空指针)：|243282|printf("x+lives+at+%25p.\n",+(void*)&x);|code-block|syntax|javascript|243283|entityMap^0|2|2|22|2|26|C|2M|5|30|C|0|I|2|10|C|0|I|5|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]|$9|T|A|U|B|C]|$9|V|A|W|B|C]|$9|X|A|Y|B|C]|$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|11|8|@$9|12|A|13|B|C]|$9|14|A|15|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|16|8|@$9|17|A|18|B|C]]|D|@]|E|$]]|$1|J|3|K|5|L|7|19|8|@]|D|@]|E|$M|N]]|$1|O|3|-4|5|6|7|1A|8|@]|D|@]|E|$]]]|P|$]]

Use <code>%p</code>, for "pointer", and don't use anything else*. You aren't guaranteed by the standard that you are allowed to treat a pointer like any particular type of integer, so you'd actually get undefined behaviour with the integral formats. (For instance, <code>%u</code> expects an <code>unsigned int</code>, but what if <code>void*</code> has a different size or alignment requirement than <code>unsigned int</code>?)

*) [See Jonathan's fine answer!] Alternatively to <code>%p</code>, you can use pointer-specific macros from <code>&lt;inttypes.h&gt;</code>, added in C99.

All object pointers are implicitly convertible to <code>void*</code> in C, but in order to pass the pointer as a variadic argument, you have to cast it explicitly (since arbitrary object pointers are only convertible, but not identical to void pointers):

<pre><code>printf("x lives at %p.\n", (void*)&amp;x);
</code></pre>

blocks|key|243296|text|作为其他(非常好的)答案的替代方案，您可以转换为uintptr_t或intptr_t+(来自stdint.h/inttypes.h)，并使用相应的整数转换说明符。这将在如何格式化指针方面提供更大的灵活性，但严格地说，不需要实现来提供这些typedefs。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|243297|entityMap^0|O|9|Y|8|1A|8|1J|A|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|G|$]]

As an alternative to the other (very good) answers, you could cast to <code>uintptr_t</code> or <code>intptr_t</code> (from <code>stdint.h</code>/<code>inttypes.h</code>) and use the corresponding integer conversion specifiers. This would allow more flexibility in how the pointer is formatted, but strictly speaking an implementation is not required to provide these typedefs.

blocks|key|2910302|text|您可以使用%25x、%25X或%25p；所有这些都是正确的。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2910303|如果您使用%25x，则地址以小写形式提供，例如：a3bfbc4|2910304|If您使用%25X，则地址以大写形式提供，例如：A3BFBC4|unordered-list-item|2910305|2910306|这两个都是正确的。|2910307|如果你使用%25x或%25X，它会考虑6个地址位置，如果你使用%25p，它会考虑8个地址位置。例如：|2910308|​|2910309|📷|atomic|2910310|2910311|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/41b764687e61628ea41fadf464527d3e.png|imageAlt^0|5|2|8|2|B|2|0|5|2|M|7|0|5|2|M|7|0|0|0|5|2|8|2|R|2|0|0|0|1|0|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@$9|15|A|16|B|C]|$9|17|A|18|B|C]|$9|19|A|1A|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|1B|8|@$9|1C|A|1D|B|C]|$9|1E|A|1F|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|1G|8|@$9|1H|A|1I|B|C]|$9|1J|A|1K|B|C]]|D|@]|E|$]]|$1|K|3|-4|5|6|7|1L|8|@]|D|@]|E|$]]|$1|L|3|M|5|6|7|1M|8|@]|D|@]|E|$]]|$1|N|3|O|5|6|7|1N|8|@$9|1O|A|1P|B|C]|$9|1Q|A|1R|B|C]|$9|1S|A|1T|B|C]]|D|@]|E|$]]|$1|P|3|Q|5|6|7|1U|8|@]|D|@]|E|$]]|$1|R|3|S|5|T|7|1V|8|@]|D|@$9|1W|A|1X|1|1Y]]|E|$]]|$1|U|3|Q|5|6|7|1Z|8|@]|D|@]|E|$]]|$1|V|3|-4|5|6|7|20|8|@]|D|@]|E|$]]]|W|$X|$5|Y|Z|10|E|$11|12|13|-4]]]]

You can use <code>%x</code> or <code>%X</code> or <code>%p</code>; all of them are correct.

<ul>
<li>If you use <code>%x</code>, the address is given as lowercase, for example: <code>a3bfbc4</code></li>
<li>If you use <code>%X</code>, the address is given as uppercase, for example: <code>A3BFBC4</code></li>
</ul>

Both of these are correct.

If you use <code>%x</code> or <code>%X</code> it's considering six positions for the address, and if you use <code>%p</code> it's considering eight positions for the address. For example:

<img src="https://i.stack.imgur.com/uOZTC.png" alt="">

Which format specifier should I be using to print the address of a variable? I am confused between the below lot.

<blockquote>
 %u - unsigned integer
 
 %x - hexadecimal value
 
 %p - void pointer
</blockquote>

Which would be the optimum format to print an address?

Correct format specifier to print pointer or address?

我应该使用哪个格式说明符来打印变量的地址？我对下面这两个问题感到困惑。 %u -无符号整数%x -十六进制值%p - void指针打印地址的最佳格式是什么？

问打印指针或地址的格式说明符是否正确？
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问打印指针或地址的格式说明符是否正确？
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