Place a zero in each element of an array passed to it in C++

Write a function & a program to test it that will place a zero in each element of an array passed to it from the calling program. Pass the size of the array as well.

#include <iostream>

using namespace std;

void zero(char [], int);

int main()

{

char a[100];

cin.getline(a,100,'\n');

zero(a,100);

cout << a << endl;

return 0;

}

void zero (char a[], int size)

{

for (int i = 0; i < size; i++)

if (a[i] != '0')

a[i] = '0';

}