Memory Allocation

The problem is the line int *a = new int[size]. Get rid of the first int (as it makes that line a variable declaration) and that should fix this problem.

Thanks! I've got another issue, but I'm going to see if I can work it out before askin' another question. Thanks again! 0/

I'm stumped. It compiles fine, but when it gets to the for function in main that prints off the array it says I don't have access to it. Here's the revised code.
#include<iostream>
#include<cstdlib>
#include<ctime>
using namespace std;
void randomArrayFill( int *a, int size )
{
a = new int[size];
for( int i = 0; i < size; i++ )
{
a = rand() % 100;
}
}

int main()
{
//----Init--------------------------------------------------------------
int size = 0;
int *a = 0;
srand(0);
//----End Init----------------------------------------------------------

cout << "Enter the size of an array to create: ";
cin >> size;

randomArrayFill( a, size );

for( int i = 0; i < size; i++ )
{
cout << a << " ";
}
cin.get();
cin.get();
return 0;
}


The variable a in main is different from the variable a in randomArrayFill because you're passing it by value. You need to pass a reference or a pointer to the variable you want to modify.
[source]
void randomArrayFill(int *&a, int size)
{
...
}
[/source]
If you're passing the pointer by value, you're only modifying a copy of the pointer which is local to the function. With a reference to the pointer, you can modify the original pointer in main.

Thanks Brother Bob! I shall read/practice with pointers some more.

It's worth pointing out that the issue you're having here is not unique to pointers. You need to understand pass-by-value and pass-by-reference, even without pointers getting involved. What does this code print?

[source lang="cpp"]
void changeValue( int a )
{
a = 42;
}

int main()
{
int a = 7;
changeValue( a );
cout << a;
return 0;
}
[/source]

Also you are leaking memory as the array you create with a = new int[size]; is never deleted. You should add a "delete [] a;" at the bottom of your main.

Note that it is idiomatic to use the return value of a function where possible:

int *randomArrayFill( int size )
{
int *result = new int[size];
for( int i = 0; i < size; i++ )
{
a = rand() % 100;
}
return result;
}


Once you have learned about memory allocation, you can then go on to use the standard library containers to avoid unnecessary manual memory management:

#include <vector>

std::vector<int> randomArrayFill( int size )
{
std::vector<int> result;
for( int i = 0; i < size; i++ )
{
a.push_back(rand() % 100);
}
return result;
}

This will prevent the memory leaks NightCreature83 mentioned.

Be aware, rip-off has a typo in his first example. The line:
a = rand() % 100;
should be
result = rand() % 100;

Like this

int *randomArrayFill( int size )
{
int *result = new int[size];
for( int i = 0; i < size; i++ )
{
result = rand() % 100;
}
return result;
}


Note that it is idiomatic to use the return value of a function where possible:
...
Once you have learned about memory allocation, you can then go on to use the standard library containers to avoid unnecessary manual memory management:
...
This will prevent the memory leaks NightCreature83 mentioned.

Just as a side note you have to learn memory management and all it's little caveats before you move onto the standard containers as not all shops use the standard containers. Some shops avoid the standard library if they can for various reasons and thus you are off having to know memory managment, also it gives you an insight into how the Standard Containers work in the background.

One note about memory management is that - depending on the APIs available to you - manual memory management may very well turn out to be more suitable for you. E.g. on Windows, a single HeapDestroy call is all that is needed to free a whole chunk of separate allocations, and without needing to keep track of individual allocations within that chunk.

Of course when learning you should treat this as an "advanced topic" and keep away from it - learn the proper way first. But do be aware that it does exist and can occasionally be a preferable choice - just don't do it yet.