arrays

[Greg]

Is there a function that will tell me the lenght of an array
ie
string array[]={"a", "b", "c", "d", "e"};
and array.size(); would return 5

[Victor Bazarov]

Greg wrote:

Is there a function that will tell me the lenght of an array
ie
string array[]={"a", "b", "c", "d", "e"};
and array.size(); would return 5

Arrays are not objects, so they don't have members, so you can't use
the dot operator. You could, however, use

template<class T, size_t s> size_t size_of(T (&a)[s]) { return s; }
...
string array[]={"a", "b", "c", "d", "e"};
size_t s = size_of(array); // 's' should be 5

Or you could try

size_t s = sizeof(array)/sizeof(array[0]);

Note, that it won't work with pointers.

V

[Mufe]

>string array[]={"a", "b", "c", "d", "e"};

size_t s = size_of(array); // 's' should be 5
This method only works if each member within array is same size.
Ex.: This wouldn't work if you declare array as
string array[]={"a", "b1", "c22", "d", "e"};

I suggest you use array of pointers so you will get identical 4byte size
of it.
Let me write it down.

char* array[] = {"a", "bc", "df" };
int count = sizeof(array)/sizeof(char*);

This will return you true count.
Victor Bazarov wrote: Greg wrote:

Is there a function that will tell me the lenght of an array
ie
string array[]={"a", "b", "c", "d", "e"};
and array.size(); would return 5

Arrays are not objects, so they don't have members, so you can't use
the dot operator. You could, however, use

template<class T, size_t s> size_t size_of(T (&a)[s]) { return s; }
...
string array[]={"a", "b", "c", "d", "e"};
size_t s = size_of(array); // 's' should be 5

Or you could try

size_t s = sizeof(array)/sizeof(array[0]);

Note, that it won't work with pointers.

V

[Alf P. Steinbach]

* Mufe:

[top-posting, possibly trolling]
Don't top-post in this group, please. See the FAQ.
* Mufe:

>string array[]={"a", "b", "c", "d", "e"};
>size_t s = size_of(array); // 's' should be 5

This method only works if each member within array is same size.

That's incorrect.

There are other limitations, though.

Ex.: This wouldn't work if you declare array as
string array[]={"a", "b1", "c22", "d", "e"};
That's incorrect.

I suggest you use array of pointers so you will get identical 4byte size
of it.

That's incorrect.

--
A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?

[Pete Becker]

Alf P. Steinbach wrote:

>string array[]={"a", "b", "c", "d", "e"};
>size_t s = size_of(array); // 's' should be 5

This method only works if each member within array is same size.

That's incorrect.

It's correct, but it's trivial: all members of an array are the same
type, hence they are all the same size.

--

Pete Becker
Dinkumware, Ltd. (http://www.dinkumware.com)

[Alf P. Steinbach]

* Pete Becker:

Alf P. Steinbach wrote:

>string array[]={"a", "b", "c", "d", "e"};
>size_t s = size_of(array); // 's' should be 5

This method only works if each member within array is same size.

That's incorrect.

It's correct, but it's trivial: all members of an array are the same
type, hence they are all the same size.

"Mufe" gave an example of what he meant, and that was inconsistent with the
meaning you read into his words. "Mufe"'s statement was incorrect. And so
your statement is also incorrect when referring to that meaning; out of
context, on the other hand, your statement is trivially true.

Cheers,

- Alf

--
A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?

[Pete Becker]

Alf P. Steinbach wrote:

* Pete Becker:

Alf P. Steinbach wrote:

>string array[]={"a", "b", "c", "d", "e"};
>size_t s = size_of(array); // 's' should be 5

This method only works if each member within array is same size.

That's incorrect.

It's correct, but it's trivial: all members of an array are the same
type, hence they are all the same size.

"Mufe" gave an example of what he meant, and that was inconsistent with the
meaning you read into his words. "Mufe"'s statement was incorrect. And so
your statement is also incorrect when referring to that meaning; out of
context, on the other hand, your statement is trivially true.

My mistake. I forgot that your goal is usually to obscure rather than to
clarify.

--

Pete Becker
Dinkumware, Ltd. (http://www.dinkumware.com)

[Alf P. Steinbach]

* Pete Becker:

Alf P. Steinbach wrote:

* Pete Becker:

Alf P. Steinbach wrote:

>>string array[]={"a", "b", "c", "d", "e"};
>>size_t s = size_of(array); // 's' should be 5
>
>This method only works if each member within array is same size.

That's incorrect.

It's correct, but it's trivial: all members of an array are the same
type, hence they are all the same size.

"Mufe" gave an example of what he meant, and that was inconsistent with the
meaning you read into his words. "Mufe"'s statement was incorrect. And so
your statement is also incorrect when referring to that meaning; out of
context, on the other hand, your statement is trivially true.

My mistake. I forgot that your goal is usually to obscure rather than to
clarify.

Yeah, I'm such a bastard that just by mentioning some -- any -- aspect of
my imagined personality you've offloaded so much Bad Karma that what's left is
so greatly improved that what you wrote earlier magically becomes correct.

Anyway, the quoting in your posting is rather incomprehensible.

Did you attempt to fix it manually?

--
A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?

[Jim Langston]

"Mufe" <mu**@nospam.net> wrote in message news:43********@news.s5.net...

string array[]={"a", "b", "c", "d", "e"};
size_t s = size_of(array); // 's' should be 5

This method only works if each member within array is same size.
Ex.: This wouldn't work if you declare array as
string array[]={"a", "b1", "c22", "d", "e"};

Array elements are ALWAYS the same size. You can't have 2 different size
elements in the same array.

I.E.
#include <iostream>
#include <string>
int main(int argc, char* argv[])
{
std::string MyString1 = "Testing";
std::string MyString2 = "X";
std::cout << sizeof( MyString1 ) << ":" << sizeof ( MyString2 ) <<
std::endl;
char x;
std::cin >> x;
return 0;
}

output in Microsoft Visual C++ .net 2003 is
28:28

All strings in MS VC++ .net 2003 then would be 28 bytes. Their data can be
any length, but is stored elsewhere, not in the object itself.

[Rui Maciel]

"Greg" <NULL> wrote:

Is there a function that will tell me the lenght of an array
ie
string array[]={"a", "b", "c", "d", "e"};
and array.size(); would return 5

Is there something in your code which forces you to use arrays instead of,
for example, a std::vector ? The vector container has that covered and it
also has many more methods which will help you a lot.
Rui Maciel
--
Running Kubuntu 5.04 with KDE 3.4.2 and proud of it.
jabber:ru********@jabber.org

[Rui Maciel]

"Greg" <NULL> wrote:

Is there a function that will tell me the lenght of an array
ie
string array[]={"a", "b", "c", "d", "e"};
and array.size(); would return 5

Is there something in your code which forces you to use arrays instead of,
for example, a std::vector ? The vector container has that covered and it
also has many more methods which will help you a lot.
Rui Maciel
--
Running Kubuntu 5.04 with KDE 3.4.2 and proud of it.
jabber:ru********@jabber.org