sizeof dinamically alocated array .... [英] sizeof dinamically alocated array....

问题描述

我有char *数组，它是dinamically alocated ....

当我把它传递给其他函数时，我需要确定这个数组的大小....

题：！？！？！sizeof操作符不符合dinamically alocated

排列工作


我怎么能确定dinamically alocated数组的大小.. ..？

请建议......

Thx！

解决方案

Mateo写道：

我有char *数组，它是dinamically alocated ....
当我把它传递给其他函数时，我需要确定这个
数组的大小....问题：sizeof运算符无法使用dinamically
分配的数组！？！？！

如何确定dinamically alocated数组的大小....？

你不能。您需要在分配时存储大小

并将其传递到同一个函数中。如果你不能这样做，不要使用一个普通的char数组，使用''std :: string''。


V

-

请在邮寄回复时从我的地址删除资金

Mateo写道：
< blockquote class =post_quotes>我有char *数组，它是dinamically alocated ....
当我把它传递给其他函数时，我需要确定这个
数组的大小...... BR />问题：！？！？！？sizeof操作符不符合dinamically alocated
我/>如何确定dinamically alocated数组的大小.... <工作br />

这是一个常见问题，但我不知道它是否在FAQ中。


答案是你应该使用std :: vector<>除非你确实需要一个

原始数组，由new []返回。


如果你有正当理由不使用std :: vector<> ，然后传递大小

与阵列。


没有便携的方法来获取这些信息，因为你的程序是

在新[]调用之后基本上抛弃了信息。不要。


-

Phlip
http://www.greencheese.org/ZeekLand < - 不是博客!!!

Phlip写道：

答案是你应该使用std :: vector<>除非你确实需要一个
原始数组，由new []返回。

更不用说传递给需要
裸T *，std :: vector< T>通过

& v [0]可以轻易转换为T *。

I have char *array and it is dinamically alocated....
When I pass it to other function, I need to determine size of this array....
Problem: sizeof operator does not work with dinamically alocated
arrays!?!?!

How can I determine size of dinamically alocated array.... ?
Please advice...
Thx!

解决方案

Mateo wrote:

I have char *array and it is dinamically alocated....
When I pass it to other function, I need to determine size of this
array.... Problem: sizeof operator does not work with dinamically
alocated arrays!?!?!

How can I determine size of dinamically alocated array.... ?

You cannot. You need to store the size at the time of allocation
and pass it into the same function. If you can''t do that, do not
use a plain char array, use ''std::string''.

V
--
Please remove capital As from my address when replying by mail

Mateo wrote:

I have char *array and it is dinamically alocated....
When I pass it to other function, I need to determine size of this
array....
Problem: sizeof operator does not work with dinamically alocated
arrays!?!?!

How can I determine size of dinamically alocated array.... ?

This is a Frequently Asked Question, but I don''t know if it''s in the FAQ.

The answer is you should use an std::vector<> unless you actually need a
primitive array, returned by new[].

If you have a legitimate reason not to use std::vector<>, then pass the size
with the array.

There''s no portable way to get this information, because your program is
essentially throwing the information away after the new[] call. Don''t.

--
Phlip
http://www.greencheese.org/ZeekLand <-- NOT a blog!!!

Phlip wrote:

The answer is you should use an std::vector<> unless you actually need a
primitive array, returned by new[].

Not to mention that for passing to library/OS routines that require a
naked T*, a std::vector<T> is trivially convertable to a T* by passing
&v[0].

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