Thread: Determining size of array returning strange values?

The following code returns 8 followed by 26, the second number obviously being correct and first being wrong despite having identical code. Any ideas what's wrong with my getarraysize function?

Code:

static char key[26] = {'r','t','c','t','b','f','n','l','a','f','s','t','t','t','s','e','a','n','i','m','(','m','o','c','i','r'};

int getarraysize(char *input) {

	int output;
	output = sizeof(input) / sizeof(input[0]);

	return output;
}

int main(int argc, char *argv[]) {

	cout << getarraysize(key) << "\n";
	cout << (sizeof(key) / sizeof(key[0]));
	return 0;
}