Array values output incorrectly - c++

Question

I am having a very simple function to input values. But I am getting a wired output. I get different values to what I am inserting? What am I doing wrong?
#include <iostream>
using namespace std;
void testFunc(float arr[], int sizeOfArray);
int main() {
int sizeOfArray = 4;
float arrA[] = {};
float arrB[] = {};
cout << "1st array VALUES" << endl;
testFunc(arrA, 4);
cout << "A -> ";
for(int i=0; i<sizeOfArray; i++){
cout << arrA[i] << " | ";
}
cout << endl;
cout << "2nd array VALUES" << endl;
testFunc(arrB, 4);
cout << endl << "B -> ";
for(int i=0; i<sizeOfArray; i++){
cout << arrB[i] << " | ";
}
cout << endl;
return 0;
}
void testFunc(float arr[], int sizeOfArray) {
for(int i=0; i<sizeOfArray; i++){
cout << "Insert val " << i+1 << ": ";
cin >> arr[i];
}
}

Answer 1

The float arrA[] = {} creates an array of floats with 0 size. When you iterate over it, you access an out of bound memory in here:
for(int i=0; i<sizeOfArray; i++);
You can list initialize an array and not specify the size of an array, using braces {...}. But in such case, the size is deduced from the elements in the list. You have empty list.
For example:
float arr[] = {}; // Empty
float arr[4]; // Four elements, all default initialized
float arr[] = {3.14, 1.61}; // Two elements, specified values
float arr[4] = {3.14, 1.61}; // Four elements, last two are value initialized
You will benefit from taking a look at these articles:
Why aren't variable-length arrays part of the C++ standard?
C++ Containers Library