Accessing Array Elements

Accessing array elements in C++ involves using array indexing, which allows you to directly access and modify specific elements within an array using their index values. This technique is fundamental in C++ and applies to both statically and dynamically allocated arrays.

Array Indexing Overview

In C++, arrays are a collection of elements of the same data type, stored in contiguous memory locations. Each element in an array can be accessed using an index, which starts at 0 for the first element.

Syntax for Array Indexing

The basic syntax for accessing an array element is:

array_name[index]

Here:

• array_name refers to the name of the array.
• index specifies the position of the element within the array.

Example: Accessing Array Elements

Here’s a simple example:

#include <iostream>
using namespace std;

int main() {
    int numbers[5] = {10, 20, 30, 40, 50};  // Declaring an array of integers

    // Accessing array elements
    cout << "First element: " << numbers[0] << endl;  // Outputs 10
    cout << "Second element: " << numbers[1] << endl; // Outputs 20

    // Modifying an array element
    numbers[2] = 60; // Changing the value of the third element

    cout << "Modified third element: " << numbers[2] << endl; // Outputs 60

    return 0;
}

Key Points to Remember

• Array Index Starts at 0: C++ arrays are zero-based, so the first element is accessed using the index 0.
• Direct Element Modification: You can modify any element using its index.
• Access Out of Bounds: Accessing an index beyond the array’s size leads to undefined behavior, which can cause errors or crashes.

Best Practices for Accessing Arrays

• Bounds Checking: C++ does not perform automatic bounds checking, so it’s your responsibility to ensure that an index is within the valid range.
• Using Loops: You can access all elements using loops such as for or while.

Example: Looping Through an Array

#include <iostream>
using namespace std;

int main() {
    int numbers[5] = {1, 2, 3, 4, 5};

    // Loop to access and display array elements
    for (int i = 0; i < 5; i++) {
        cout << "Element at index " << i << ": " << numbers[i] << endl;
    }

    return 0;
}