Using uninitilized variable in a method - c++

Question

I'm writing a simple program within which a dynamic array is to be created. The function that is being used to create said array is in a second .cpp file, attached as a user-made library. Unfortunatelly Visual Studio pops an error saying that the program can't use uninitialized variable. I feel like it's a really easy problem to solve, but I don't know how to get through it. Here is the code:
int main()
{
int i = 5, j = 6;
string** Array;
createDefStruct(Array, i, j);
/*for (int k = 0; k < i; k++)
{
for (int m = 0; m < j; m++)
{
Array[i][j] = "YIKES";
cout << Array[i][j] << '\t';
}
cout << endl;
}*/
deleteDefStruct(Array, i);
return 0;
}
The createDefStruct function:
void createDefStruct(string** Arr, int varAttribCount, int varCount)
{
Arr = new string * [varAttribCount+1];
for (int i = 0; i < varAttribCount+1; i++)
Arr[i] = new string[varCount];
}
How do I go about initilizing a variable?
Thank you in advance!

Answer 1

So the problem is that instead of returning your array from the function you passed the array into the function as parameter. This mean that the variable is uninitialised in main (even though it is initiialised in createDefStruct). Rewrite like this
string** createDefStruct(int varAttribCount, int varCount)
{
string** Arr = new string * [varAttribCount+1];
for (int i = 0; i < varAttribCount+1; i++)
Arr[i] = new string[varCount];
return Arr;
}
int main()
{
int i = 5, j = 6;
string** Array = createDefStruct(i, j);
...
In general when you want a function to return a value you use return from inside the function to return that value. When you want to pass a value into a function you use a parameter. In your createDefStruct function varAttribCount and varCount are the parameters but the array should be a return value.