I understand how arrays decay to pointers. I understand that, for the compiler, this:
我理解数组如何衰减到指针。我明白,对于编译器,这个:
void foo(int *arg1);
is 100% equivalent to this:
是100%相当于:
void foo(int arg1[]);
Should one style be preferred over the other? I want to be consistent, but I'm having a hard time justifying either decision.
一种风格应该优先于另一种吗?我希望保持一致,但我很难为两种决定辩护。
Although int main(int argc, char *argv[]) and int main(int argc, char **argv) are the same, the former seems to be much more common (correct me if I'm wrong).
虽然int main(int argc,char * argv [])和int main(int argc,char ** argv)是相同的,但前者似乎更常见(如果我错了,请纠正我)。
2 个解决方案
#1
7
I would recommend against using the [] syntax for function parameters.
我建议不要使用函数参数的[]语法。
The one argument in favour of using [] is that it implies, in a self-documenting way, that the pointer is expected to point to more than one thing. For example:
支持使用[]的一个论点是,它以自我记录的方式暗示指针应指向多个事物。例如:
void swap(int *x, int *y)
double average(int vals[], int n)
But then why is char * always used for strings rather than char []? I'd rather be consistent and always use *.
但是为什么char *总是用于字符串而不是char []?我宁愿保持一致,也总是使用*。
Some people like to const everything they possibly can, including pass-by-value parameters. The syntax for that when using [] (available only in C99) is less intuitive and probably less well-known:
有些人喜欢const他们可能做的一切,包括传值参数。使用[]时的语法(仅在C99中可用)不太直观,可能不太为人所知:
const char *const *const words vs. const char *const words[const]
const char * const * const words vs. const char * const words [const]
Although I do consider that final const to be overkill, in any case.
虽然我确实认为最终的const是过度的,无论如何。
Furthermore, the way that arrays decay is not completely intuitive. In particular, it is not applied recursively (char words[][] doesn't work). Especially when you start throwing in more indirection, the [] syntax just causes confusion. IMO it is better to always use pointer syntax rather than pretending that an array is passed as an argument.
此外,阵列衰减的方式并不完全直观。特别是,它不是递归应用的(char words [] []不起作用)。特别是当你开始抛出更多的间接时,[]语法只会引起混淆。 IMO最好总是使用指针语法,而不是假装数组作为参数传递。
More information: http://c-faq.com/~scs/cgi-bin/faqcat.cgi?sec=aryptr#aryptrparam.
更多信息:http://c-faq.com/~scs/cgi-bin/faqcat.cgi?sec = aaryptr #aryptrparam。
#2
3
Except for char*, I use Type array[N], where N is some number or a defined constant, when the passed item conceptually is an array (i.e., it contains N>1 elements), Type * pointer when the passed item is a pointer to exactly one object.
除了char *之外,我使用Type array [N],其中N是某个数字或定义的常量,当传递的项目在概念上是一个数组时(即,它包含N> 1个元素),当传递的项目为时,键入*指针指向一个对象的指针。
I tend to use std::vector if the array is of a variable size. C99's concept of variable sized arrays is not available in C++.
如果数组的大小可变,我倾向于使用std :: vector。 C99的可变大小数组的概念在C ++中不可用。
#1
7
I would recommend against using the [] syntax for function parameters.
我建议不要使用函数参数的[]语法。
The one argument in favour of using [] is that it implies, in a self-documenting way, that the pointer is expected to point to more than one thing. For example:
支持使用[]的一个论点是,它以自我记录的方式暗示指针应指向多个事物。例如:
void swap(int *x, int *y)
double average(int vals[], int n)
But then why is char * always used for strings rather than char []? I'd rather be consistent and always use *.
但是为什么char *总是用于字符串而不是char []?我宁愿保持一致,也总是使用*。
Some people like to const everything they possibly can, including pass-by-value parameters. The syntax for that when using [] (available only in C99) is less intuitive and probably less well-known:
有些人喜欢const他们可能做的一切,包括传值参数。使用[]时的语法(仅在C99中可用)不太直观,可能不太为人所知:
const char *const *const words vs. const char *const words[const]
const char * const * const words vs. const char * const words [const]
Although I do consider that final const to be overkill, in any case.
虽然我确实认为最终的const是过度的,无论如何。
Furthermore, the way that arrays decay is not completely intuitive. In particular, it is not applied recursively (char words[][] doesn't work). Especially when you start throwing in more indirection, the [] syntax just causes confusion. IMO it is better to always use pointer syntax rather than pretending that an array is passed as an argument.
此外,阵列衰减的方式并不完全直观。特别是,它不是递归应用的(char words [] []不起作用)。特别是当你开始抛出更多的间接时,[]语法只会引起混淆。 IMO最好总是使用指针语法,而不是假装数组作为参数传递。
More information: http://c-faq.com/~scs/cgi-bin/faqcat.cgi?sec=aryptr#aryptrparam.
更多信息:http://c-faq.com/~scs/cgi-bin/faqcat.cgi?sec = aaryptr #aryptrparam。
#2
3
Except for char*, I use Type array[N], where N is some number or a defined constant, when the passed item conceptually is an array (i.e., it contains N>1 elements), Type * pointer when the passed item is a pointer to exactly one object.
除了char *之外,我使用Type array [N],其中N是某个数字或定义的常量,当传递的项目在概念上是一个数组时(即,它包含N> 1个元素),当传递的项目为时,键入*指针指向一个对象的指针。
I tend to use std::vector if the array is of a variable size. C99's concept of variable sized arrays is not available in C++.
如果数组的大小可变,我倾向于使用std :: vector。 C99的可变大小数组的概念在C ++中不可用。