Cannot convert parameter 1 from 'int' to 'int []' - c++

Question

For an assignment for my programming class, I am getting this error:
Error 1 error C2664: 'binarySearch' : cannot convert parameter 1 from 'int' to 'int []' Line 34.
#include<iostream>
using namespace std;
int selectionSort(int[], int);
int binarySearch(int[], int, int);
int sorted;
int main()
{
int size;
int i;
int desirednum;
cout << "How many values do you want to enter?";
cin >> size;
int* userarray = 0;
userarray = new int[size];
for (i = 0; i < size; i++)
{
cout << "Enter a value: ";
cin >> userarray[i];
}
int sorted = selectionSort(userarray, size);//calls the selection sort function
cout << "What value are you looking for: ";//asks what value they are searching for
cin >> desirednum;
int location = binarySearch(sorted, size, desirednum);
delete[] userarray;
return 0;
}
int selectionSort(int numbers[], int size)
{
int i, j, min, minidx, temp, desirednum, sorted = 0;
cout << "What value are you looking for: ";
cin >> desirednum;
for (i = 0; i < (size - 1); i++)
{
min = numbers[i];
minidx = i;
for (j = i + 1; j < size; j++)
{
if (numbers[j] < min)
{
min = numbers[j];
minidx = j;
}
}
if (min < numbers[i])
{
temp = numbers[i];
numbers[i] = min;
numbers[minidx] = temp;
sorted++;
}
}
return sorted;
}
int binarySearch(int& user_array, int amount, int value)
{
int left, right;
int* middle;
left = 0;
right = amount - 1;
while (left <= right)
{
middle = (int*)((left + right) / 2);
if (value == user_array[middle])
{
return *middle;
}
}
}

Answer 1

Your signature (the declaration) is
int binarySearch(int[], int, int);
But your definition is:
int binarySearch(int& user_array, int amount, int value)
This is not the same. The user_array is simply taking an int by reference. You want to take in an array (or a pointer).
As an aside, amount is rather misleading. size would be more accurate and typical.
Here's an example of the expected syntax and usage:
void printArray(int array[], int size) {
for(int i = 0; i < size; ++i) {
std::cout << array[i];
}
}
// Usage
int array[] = {1,2,3};
printArray(array, 3);
Note that the type of the parameter is int[] and not int& (which is merely a reference to an int). You can also use int*.

Answer 2

I haven't looked at C++ in a bit but I can tell in your call to your binarysearch() function, you are passing in a single int and not an integer array. You are passing in the variable "sorted" into binarysearch as the first parameter. "sorted" was declared as int and was assigned the return value of the selectionsort function. selectionsort() is defined with a return type of int.
I think the main problem is you should be passing in the variable "userarray" as the first parameter to binarysearch(). Look at the name if the first parameter to binarysearch().
The value being returned from selectionsort (sorted) appears to only be a counter keeping track of how many swaps had to occur in order to perform the selection sort. If you don't need that info (I don't see any use of that variable) then you could make the selectionsort a void function.
Edit - Also (thanks to Mike), I just noticed the differences in the function declaration vs. definition.