Question

When you pass an array name as an argument to a function, what is actually being passed?

Short answer

Answer: When we pass an array name as an argument to a function, we are actually passing the base address of the array, i.e., the memory address of the first element. In other words, we are passing a pointer to the array.

Step-by-step solution

Understand Arrays and Functions

Before diving into the concept of passing an array name as an argument to a function, let's first understand what arrays and functions are in programming. An array is a collection of elements of the same data type, stored in contiguous memory locations, and can be accessed using indices. A function, on the other hand, is a group of statements that perform a specific task.

Initializing an Array

To access an array's elements, we need to initialize it. Let's say we declare an array named arr with 5 integers: int arr[5] = {10, 20, 30, 40, 50};

Creating a Function

Next, let's declare a function that receives an array as an argument and performs a certain task with its elements. For simplicity, let's create a function to calculate the sum of the array's elements: int array_sum(int input_arr[], int size);

Passing an Array Name to a Function

When we pass the array name as the argument to the function, we are actually passing the base address (i.e., the memory address of the first element) of the array. In other words, we are passing a pointer to the array. In our example, the function call would look like this: int sum = array_sum(arr, 5);

Accessing Array Elements inside the Function

Inside the function, we can access the array elements by using pointer arithmetic to navigate through the contiguous memory locations. Also, since we're working with pointers now, the formal parameter in the function definition should be a pointer: int array_sum(int *input_arr, int size) { int sum = 0; for (int i = 0; i < size; i++) { sum += input_arr[i]; } return sum; } This way, the function works with the original array and not a copy of it, thus minimizing the memory usage.