C++ Arrays Tutorial

1. Declaring an Array

An array is declared using the syntax:

int numbers[5]; // Declares an array of 5 integers
                

Here, numbers can hold 5 integers, indexed from 0 to 4.

2. Initializing an Array

You can initialize an array at the time of declaration:

int numbers[5] = {10, 20, 30, 40, 50};
                

Elements are assigned in the order specified in the initializer list.

3. Accessing Array Elements

Use the index to access or modify elements:

#include <iostream>
using namespace std;

int main() {
    int numbers[3] = {10, 20, 30};
    cout << "First element: " << numbers[0] << endl; // Access
    numbers[2] = 50; // Modify
    cout << "Modified third element: " << numbers[2] << endl;
    return 0;
}
                

4. Multidimensional Arrays

C++ supports arrays with multiple dimensions:

#include <iostream>
using namespace std;

int main() {
    int matrix[2][3] = {
        {1, 2, 3},
        {4, 5, 6}
    };

    cout << "Element at (1,2): " << matrix[1][2] << endl;
    return 0;
}
                

This example demonstrates a 2x3 array. Access elements using matrix[row][column].

5. Iterating Over Arrays

Use loops to process arrays:

#include <iostream>
using namespace std;

int main() {
    int numbers[4] = {5, 10, 15, 20};

    for (int i = 0; i < 4; i++) {
        cout << "Element " << i << ": " << numbers[i] << endl;
    }
    return 0;
}
                

This example uses a for loop to print all array elements.

6. Common Mistakes

• Accessing out-of-bounds indices, leading to undefined behavior.
• Not initializing arrays, which can result in garbage values.