C语言 从指针打印地址时 %lx 和 %ld 有什么区别？
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What is the difference between %lx and %ld when printing an address from pointer?
提问by Ray
I have tried googling the first one for %lx, but I have no good results, BUT I have successfully searched up %ld which is just long int. Necessary for printing addresses I guess, but what is %lx for?
我试过在谷歌上搜索 %lx 的第一个，但我没有好的结果，但我已经成功搜索了 %ld，它只是 long int。我猜是打印地址所必需的，但是 %lx 有什么用？
This is where I am confused:
这是我感到困惑的地方：
int main()
{
int value = 25;
int *pointer = &value;
printf("%ld\n", pointer); // prints out the address of variable value( I hope)
printf("0x%lx\n", pointer); // Completely confused here, is this perhaps address in hex?
}
Would be awesome if someone can clear this confusion I am having!
如果有人能清除我遇到的这种困惑，那就太棒了！
I have ran this code, and I have the results, but I am still not sure what the lx does..I have seriously tried googling this "%lx" in google, but no results explaining it.
我已经运行了这段代码，我得到了结果，但我仍然不确定 lx 是做什么的。
Edit: if I use 'p' to print address then have I been wrong in thinking %ld prints address? Confused.
编辑：如果我使用“p”来打印地址，那么我认为 %ld 打印地址是错误的吗？使困惑。
回答by Bill Lynch
They're both undefined behavior.
它们都是未定义的行为。
To print a pointer with printf, you should cast the pointer to void *and use "%p".
要使用 printf 打印指针，您应该将指针强制转换为void *并使用"%p".
That being said:
话虽如此：
We can talk about the difference between "%ld"and "%lx"when trying to print integers. %ldexpects a variable of type long int, and %lxexpects a variable of type long unsigned int.
我们可以讨论"%ld"和"%lx"尝试打印整数之间的区别。%ld需要一个类型的变量long int，并%lx需要一个类型的变量long unsigned int。
More or less though, The difference between x, o, dand uare about how numbers are going to be printed.
或多或少x，o、d和之间的区别在于u如何打印数字。
xprints an unsigned number in hexadecimal.oprints an unsigned number in octal.uprints an unsigned number in decimal.dprints a signed number in decimal.iprints a signed number in decimal.
x以十六进制打印一个无符号数。o以八进制打印一个无符号数。u以十进制打印一个无符号数。d以十进制打印有符号数。i以十进制打印有符号数。
We can then attach lto the format string for formats like %lxto specify that instead of an int, we're using a long int(That is, an unsigned long int, or long int).
然后，我们可以将l格式附加到格式字符串上，例如%lx指定int我们使用的是 a long int（即 anunsigned long int或long int）而不是 an 。
There is a table at cppreference that has additional information: http://en.cppreference.com/w/c/io/fprintf
cppreference 中有一个表，其中包含其他信息：http: //en.cppreference.com/w/c/io/fprintf
回答by Farouq Jouti
%pand %lxprints the address in hexadecimal while %ldprints it in decimal
%pand %lxprints the address in hexadecimal while %ldprints it in decimal
