How to i get my Array to output its random generated values from 0

I wanted to make a function called fillArray to set up random values to the Array. Then i wanted the function to output all the values but i kept getting values way above 99.

This is what i have written so far:

#include <ctime>
#include <iostream>

using namespace std;

void fillArray(){
    srand(time(NULL));

    const unsigned int sizeOfArray = 10; // this sets the array to the constant size of 10
    int numberArray[sizeOfArray];  //this sets the array to the size of 'sizeOfArray' which is 10

    for(int i = 0; i < sizeOfArray; i  )
    {
      numberArray[i] = rand() % 100;
      cout << numberArray[i] << endl;
    }
}


int main (){
    void fillArray(int a[10], int randNum);
    cout << numberArray[0] << " , " << numberArray[1] << " , " << numberArray[2] << " , " << numberArray[3] << " , " << numberArray[4] << " , " << numberArray[5] << " , " << numberArray[6] << " , " << numberArray[7] << " , " << numberArray[8] << " , " << numberArray[9] << '\n';

}

I understand the name numberArray hasnt been declared in the main function but just wondered what to do.

CodePudding user response：

So, your error is simple:

You have declared a function in the main function like this:

int main()
{
  void fillArray(int a[10], int random);
}

But it should have been

int main()
{
  fillArray(int a[10], int random);
}

Which is calling the fillArray function Also there are a few other things that i would like to add,

instead of fillArray taking nothing it should take an array like this

  template<auto Size>
  void fillArray(int (&arr)[Size])
  {
    // Implemenatation
  }

and also, it should not take a random number the function can do that in the function body.

When you are printing your array, you should use a loop or a specialized function to do it like this:

template<auto Size>
auto PrintArray(int (&arr)[Size])
{
  for(int i = 0; i < Size; i  )
  {
    std::cout << arr[i] << ", ";
  }
  std::cout << "\n";
}

So, your final code would be something like the following:

#include <ctime>
#include <iostream>

using namespace std;

template<auto Size>
void fillArray(int (&numberArray)[Size]){
    srand(time(NULL));

    for(int i = 0; i < Size; i  )
    {
      numberArray[i] = rand() % 100;
    }
}

template<auto Size>
auto PrintArray(int (&arr)[Size])
{
  for(int i = 0; i < Size; i  )
  {
    std::cout << arr[i] << ", ";
  }
  std::cout << "\n";
}

int main (){
    int numberArray[10];
    void fillArray<10>(numberArray);
    PrintArray<10>(numberArray);

}

CodePudding user response：

The fillArray() function is not being called. You declared fillArray as - void fillArray(). But when you call fillArray it is called as - fillArray(int a[10], int randNum). This line does not call the function declared earlier as the number of parameters is different. The original fillArray() function does not accept any parameters but it is called with two. Moreover, we never write the return type when we call a function. Call the function as fillArray() and it will work. Remember that the function call and the function declaration should be exactly same.

Regarding the not declared in scope problem, your array is declared in the fillArray function and thus not accessible in the main method. To solve this either make your array global and declare it outside the function after the namespace line or just don't use it in the main function. Just call fillArray() from the main method and it will populate and print the array for you.