RE: [Dev-C++] sizeof array

[Ioannis V. <no...@ho...>]

> -----Original Message-----
> From: Ramana Kumar [mailto:ra...@my...] 
> Sent: Thursday, August 01, 2002 11:57 AM
> To: Ioannis Vranos; C++
> Subject: RE: [Dev-C++] sizeof array
> 
> 
> Vectors would be great, except for the fact that i can't 
> initialise them
> using {...}
> which is the only convenient way to do something like
> {
>  "YOU'RE","YOU ARE",
>  "I'M","I AM",
> }
> and i have checked that vectors can't be initialised by 
> passing them an
> array.


Of course you can:


#include <vector>
#include <string>


int main()
{
  using namespace std;
  
  char temparray[4][20]={"YOU'RE","YOU ARE", "I'M","I AM"};
  

  vector<string>array(&temparray[0], &temparray[4]);       
}






> so, i have three options remaining.
> 1. this is quite inelegant, but since arrays are initialised 
> with {...}, can
> i not pass a value in {} directly to the function so that the 
> parameter is
> treated as a local array within the function?


You must understand something. Objects (including arrays) are passed by
reference only by using a pointer or reference. In the case of an built
in array it is a pointer or reference too its first element.



sizeof() does not see an array since an array is not passed, a variable
pointer pointing to the first element is passed. In case of C-style
strings you have not such a problem since there is '\0' and strlen().
But why mess with this C-style low level (and unecessary) stuff?







> 2. i assume this is not possible, but perhaps since the 
> function receives a
> pointer to the first element of a array, i can somehow 
> dereference this to
> get the whole array or something like that?


By dereferencing it you get the value of the pointed element (in your
example of the char).



> 3. this is what i will have to do soon... just write the array locally
> thanks for all your help so far


Or use standard library facilities. :)




Ioannis

* Ioannis Vranos
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