Question

This is an assignment i am working on for class. To make a long story short i am attempting to call the allocate() function in main to execute. I keep getting the error that testArray was not declared in this scope”. I am a bit confused, If my return statement is being called through my function than how can it not be in scope? I hope this is making sense, I am confusing myself with these pointers and functions. Any suggestions are appreciated, thanks.

#include <iostream>
using namespace std;

int* allocate(int&);

int* allocate(int &numOfScores)
{

    int *testArray;

    //prompt user for scores
    cout << "How many test scores would\n";
    cout << "you like to process: " << endl;
    cin >> numOfScores;

    //dynammically allocate an arrray to hold the scores
    testArray = new int[numOfScores];

    //get the scores from user
    for(int count = 0; count < numOfScores; count++)
    {
        cout << "Enter Score: " << endl;
        cin >> testArray[count];
    }


    //release the memory that was allocated for *ptr 
    delete [] testArray;
    testArray = 0;

    return testArray;
}

int main()
{   

    allocate(testArray);

    return 0;

}

Answer 1

This is because you are refering to testArray as though it was defined in the current function what you actually need is

#include <iostream>
using namespace std;

int* allocate(int&);

int* allocate(int &numOfScores)
{

    int *testArray;

    //prompt user for scores
    cout << "How many test scores would\n";
    cout << "you like to process: " << endl;
    cin >> numOfScores;

    //dynammically allocate an arrray to hold the scores
    testArray = new int[numOfScores];

    //get the scores from user
    for(int count = 0; count < numOfScores; count++)
    {
        cout << "Enter Score: " << endl;
        cin >> testArray[count];
    }


    //release the memory that was allocated for *ptr 
    delete [] testArray;
    testArray = 0;

    return testArray;
}

int main()
{   
    int* testArray;
    int numberOfScores;
    testArray=allocate(numberOfScores);
    delete[] testArray;
    return 0;
}

However I would discourage this style of coding. You should looking into using std::vectors.

for example

size_t nun_scores;  
std::cin >> nun_scores;
std::vector<int> scores(num_scores);
//so on

http://en.cppreference.com/w/cpp/container/vector