When an array is passed to a function, the function has access to the original array.

Before diving into the solution, it is crucial to know how arrays and functions work. An array is a collection of elements of the same type, stored in contiguous memory locations. A function, on the other hand, is a block of code that performs a specific task.

When an array is passed to a function, it is passed by reference. This means that the function receives a reference (memory address) to the original array, instead of a copy of its elements. This allows the function to access and modify the original array.

Let's demonstrate this by using a simple example in C. In this example, we will create a function that takes an array as input and multiplies each element by 2. ```c #include void multiplyArray(int arr[], int size) { // function definition for(int i = 0; i < size; i++) { arr[i] = arr[i] * 2; } } int main() { int numbers[] = {1, 2, 3, 4, 5}; int length = sizeof(numbers) / sizeof(numbers[0]); multiplyArray(numbers, length); // function call for(int i = 0; i < length; i++) { printf("%d ", numbers[i]); // output: 2 4 6 8 10 } return 0; } ```

In this example, we create an array called 'numbers' with five elements in the main function. We then calculate its length using the `sizeof` operator. After that, we call the `multiplyArray` function, which takes the array and its size as parameters. ```c multiplyArray(numbers, length); // function call ``` Inside the `multiplyArray` function, we loop through the array and multiply each element by 2. ```c for(int i = 0; i < size; i++) { arr[i] = arr[i] * 2; } ``` When the function finishes executing, we go back to the main function, where we then loop through the 'numbers' array and print its elements. Since the function had access to the original array, the elements are now doubled: 2, 4, 6, 8, and 10. If the array was passed by value (creating a copy), the printed elements would have remained the same - 1, 2, 3, 4, and 5. But, as arrays are passed by reference, it allowed the function to modify the original array directly.