Question

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

Short answer

When an array name is passed as an argument to a function, what is actually being passed is a reference or a pointer to the first element of the array. This approach allows the function to efficiently access and manipulate the original array elements, without creating a copy of the entire array. The key concept is understanding pointers or references, which store memory addresses of other variables or data. Function parameters should be declared accordingly, and array elements can be accessed within the function using indexing notation or pointer arithmetic.

Step-by-step solution

Introduction

When an array name is passed as an argument to a function, it is not passing the entire array. Instead, it passes a reference or a pointer to the memory location of the first element of the array.

Understand pointers/references

Pointers and references are variables that store the memory address of another variable or data. In the context of passing an array to a function, the reference or pointer to the first element of the array is shared, allowing the function to access the memory location of the array's elements.

Function Declaration and Call

When the function is declared, its parameter should indicate that it is expecting a pointer or a reference to an array element. For example, in C++: ```cpp void myFunction(int *arr) { /*...*/ } ``` When the function is called, the array name is passed as an argument without square brackets ([]): ```cpp int main() { int myArray[] = {1, 2, 3}; myFunction(myArray); } ```

Array Access in the Function

Inside the function, elements of the array can be accessed using the pointer arithmetic or by using the indexing notation. For example, in C++: ```cpp void myFunction(int *arr) { for (int i = 0; i < 3; ++i) { cout << arr[i] << " "; // using indexing notation cout << *(arr + i) << " "; // using pointer arithmetic } } ```

Conclusion

When an array name is given as an argument to a function, what is actually being passed is a reference or a pointer to the first element of the array. This allows the function to access the original array elements through that memory address efficiently, without creating a copy of the entire array.