C++ Array of Pointers not assignable - c++

Question

I need to create 2 arrays, each with 4 elements. One array contains four int values gotten from the user, and the other array contains pointers to the elements of the first array. I keep getting the following error:
array type 'int *[4]' is not assignable
on this line:
my_ptrs = &my_ints;
Here is my code:
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int my_ints[4];
int *my_ptrs[4];
float temp;
int num;
for (int x=0; x< 4; x++)
{
cout << "Enter Integer:" << endl;
cin >> num;
my_ints[x] = num;
}
my_ptrs = &my_ints;
for(int k=0; k<=3; k++)
{
for(int j=k+1; j<=3; j++)
{
if(my_ptrs[k]>my_ptrs[j])
{
temp=*my_ptrs[k];
my_ptrs[k]=my_ptrs[j];
*my_ptrs[j]=temp;
}
}
cout << my_ptrs[k] << " ";
}
return 0;
}

Answer 1

Your apparent intent is to have each pointer in my_ptrs to point to the corresponding value in my_ints.
I'm afraid there are no shortcuts here, using a single assignment. You have to do it the hard way:
for (int i=0; i<4; ++i)
my_ptrs[i]=&my_ints[i];

Answer 2

You cannot assign a pointer-to-an-array to an array variable, like you are trying to do. But what you can do instead is either:
initialize the second array in its declaration directly:
int my_ints[4];
int* my_ptrs[4] = {&my_ints[0], &my_ints[1], &my_ints[2], &my_ints[3]};
populate the array in a separate loop:
int my_ints[4];
int* my_ptrs[4];
for (int i = 0; i < 4; ++i)
my_ptrs[i] = &my_ints[i];
That being said, based on what you are trying to do ("i want to print the my_ptrs array in ascending order"), you could just get rid of the second array altogether and use the std::sort() algorithm instead:
Sorts the elements in the range [first, last) in ascending order.
#include <iostream>
#include <algorithm>
using namespace std;
int main()
{
int my_ints[4];
for (int x = 0; x < 4; ++x)
{
cout << "Enter Integer:" << endl;
cin >> my_ints[x];
}
std::sort(my_ints, my_ints+4);
for(int k = 0; k < 4; ++k)
cout << my_ints[k] << " ";
return 0;
}