Converting argv arguments to int - c++

Question

I have tried atoi, strol, and stoi but none of them are working for me. I've even tried to subtract '0' from the char which I heard should work but that threw an error too. atoi gives me a Segmentation Fault, strol won't compile, and stoi gives me an std logic error. here is my entire program as of right now:
#include <iostream>
#include <string>
#include <stdlib.h>
using namespace std;
bool isPrime(int);
int main (int argc, char *argv[])
{
const int size = 199;
int counter = 1;
int primeAry[size];
for (int i = 0; i < size; i++) // creates an array of prime numbers
{
if (isPrime(i))
{
primeAry[counter] = i;
counter++;
}
}
for (int j = 1; j <= argc; j++) // finds prime numbers by index of args and displays them
{
if (j == 1)
cout << "Last name is " << argv[j] << endl;
else
{
int temp = atoi(argv[j]);
cout << temp << " th prime number is " << primeAry[temp] << endl;
}
}
system("pause");
return 0;
}
bool isPrime(int num)
{
if(num <= 1)
return false;
else if (num <= 3)
return true;
else if (((num % 2) == 0) || (num % 3) == 0)
return false;
int i = 5;
while((i*i) <= num)
{
if ((num % i == 0) || ((num % (i + 2)) == 0))
return false;
i = i + 6;
}
return true;
}
And here is the result I get:
Last name is smith
1 th prime number is 2
2 th prime number is 3
3 th prime number is 5
Segmentation Fault
I've been working on this forever and I've searched every forum that I could find but I can't figure out what I'm missing.

Answer 1

Segmentation Fault**
You get segmentation fault when you pass NULL to atoi. This is happening because your loop bounds are incorrect. This:
for (int j = 1; j <= argc; j++)
should instead be
for (int j = 1; j < argc; j++)
In C, you should treat all loops with <= terminating condition with extreme suspicion. More often than not that's where the bug is hiding.