Re: sizeof array via pointer
* Mark S.:
Hi,
I want to access an array via a pointer and get the size of the array,
but sadly I don't know the correct syntax for it:
int main()
{
char c[10];
char* cp = c;
cp[3] = 'b'; // works
int a = sizeof(cp); // this doesn't (returns 4 - why???)
It giveth the size of the pointer.
a = sizeof(*cp); // neither does this (returns 1)
It giveth the size of the pointer's referent, a 'char'.
}
So how do I get the correct size of c via the pointer (of course, the
goal is to use this within a function)???
You can't get the array size via the pointer.
The information simply isn't there, at least as far as standard C++ is concerned.
Instead of raw arrays, use a std::vector or a std::string.
#include <vector>
#include <iostream>
int main()
{
using namespace std;
vector<char> c( 10 );
c.at( 3 ) = 'b';
cout << v.size() << endl;
}
Cheers & hth.,
- Alf
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