Need help passing arrays, and input arrays - c++

Question

So this is a topic that is often confused, the arrays are always passed by reference.
The point of this program is to have a company figure out how much food their kittens are eating weekly.
So the program works well however whenever I go to send my food values ,,, that the use inputs themselves, (these are the amounts of food each kitten is eating weekly), its sending back values that arent what i'm trying to pass, theyre just random numbers in memories, and i assumed that its because im not returning a value, but i read that these values are passed by reference and that you do not need to return a value,
Please help!
#include <iostream>
using namespace std;
void kittyfood(string kittyNames[], int sizeOfArray); //prototype for kittyfood function
void report(string kittyNames[], int sizeOfArray, float food[]); //prototype for report function
int main()
{
string names[5]={"Fluffy","Sneaky","Moonie","Stuffy","Oriana"}; //set cat names to the array
float food[5]; //float array for food amounts with 5 elements
kittyfood(names,5); //call too kittyfood function passing the kitty names and the size of array
report(names,5,food); //call to report function with kitty names, size of array, and ammount of foods
return 0;
}
void kittyfood(string kittyNames[], int sizeOfArray)
{
float food[5];
for (int i=0;i<sizeOfArray; i++) //loop to go through cat names and get the amounts of food they eat
{
cout << "Please enter the amount of food in pounds "<< kittyNames[i] << " eats weekly\n"; //prompt user food eaten
cin >> food[i]; //user input food eaten
while (food[i]<0)
{
cout << "This cannot be a negative ammount \n"; //input validation
cin >> food[i];
}
}
}
void report(string kittyNames[], int sizeOfArray, float food[])
{
float smallest, largest; //declaration for the smallest and largest amount
string smallestName, largestName; //declaration for the cat that eats the most or least
smallest=largest=food[0]; //initialize the smallest and largest at the first array food value
smallestName=largestName=kittyNames[0]; //initialize for the smallest and largest eaten for the first cat name in array
float totalFood; //declaration
totalFood=0; //initialization
for (int i=0;i<sizeOfArray; i++) //loop to go through cats and display their name and amount of food they ate
{
cout << kittyNames[i] << " eats "<< food[i]<< " pounds of food weekly \n";
if (smallest > food[i])
{
smallest = food[i]; //if the food amount is less than the original value then replace it
smallestName=kittyNames[i]; //change the name of the cat to the new cats name
}
if (largest < food[i])
{
smallest = food[i]; //if the food amount is more than the original then replace it
largestName = kittyNames[i]; //change the name of the cat to thew new cats name
}
totalFood+=food[i]; //keep adding the amounts of food to the total each time the loop goes through
}
cout << endl<<smallestName << " ate the least amount of food at " << smallest << " pounds \n"; //display the lowest cats name + ammount
cout << largestName << " ate the most amount of food at " << largest << " pounds \n"; //display the largest cats name + ammount
cout << "The total amount of food eaten weekly is "<<totalFood<<endl; //display total food eaten
}

Answer 1

The problem is that food inside the kittyfood function is a local variable and not the same as the array you have created in your main function.
The local variable gets destroyed after the function has returned and the one on main is still uninitialized thus containing garbage values.

Answer 2

The food array in main is not the same as the food array in kittyfood. In kittyfood you're populating a local to the function array with some values. As a result the array in main has undefined contents.
You could pass the food array to kittyfood as well, like so:
int main()
{
string names[5]={"Fluffy","Sneaky","Moonie","Stuffy","Oriana"};
float food[5];
kittyfood(names, food, 5);
}
void kittyfood(string kittyNames[], float food[], int sizeOfArray)
{
// populate the food array
}
Or you could use std::vector or std::array to make your life easier, but that is beside the question.

Answer 3

You read amount of food (float food[5]; variable) from standard input in kittyfood function and never use it. I guess this will help you.
void kittyfood(string kittyNames[], int sizeOfArray, float food[])
{
for (int i=0;i<sizeOfArray; i++) //loop to go through cat names and get the amounts of food they eat
{
cout << "Please enter the amount of food in pounds "<< kittyNames[i] << " eats weekly\n"; //prompt user food eaten
cin >> food[i]; //user input food eaten
while (food[i]<0)
{
cout << "This cannot be a negative ammount \n"; //input validation
cin >> food[i];
}
}
}