print an array in c++

[ppgengen]

how come the script below only prints out the first element of the array? how should I modify it?

// arrays as parameters
#include <iostream>
using namespace std;

void printarray (int arg[]) {


for (int n=0; n<(sizeof(arg)/sizeof(*arg)); n++)
cout << arg[n] << ", ";
cout << "\n";
}

int main ()
{
int firstarray[] = {5, 10, 15};
int secondarray[] = {2, 4, 6, 8, 10};
printarray (firstarray);
printarray (secondarray);
return 0;
}



Thanks for your help,

Gen

[RRick]

sizeof(arg) = sizeof(*int) = 4
sizeof(*arg) = sizeof(int) = 4
4 / 4 = 1

Your arg[] declaration declares a int *, and sizeof has no idea how many ints you have in the array.

You'll have to use other techniques to figure out how many ints are in your arrary.

• You can pass an extra parameter that defines the size of the arrary.
• Put a "last" int value in the array. The problem with this is picking an int that doesn't show up in the array. This is the technique that strings use. They use a '\0' as the last character value for a string.