Introduction to Arrays in C++ Tutorial

Introduction

Arrays are a fundamental data structure in C++ used to store multiple values of the same type in a single variable. They are stored in contiguous memory locations and allow efficient access using an index.

What is an Array?

An array is a collection of elements of the same data type stored under a single name. Each element is accessed by its index (position) starting from 0.

Key Points:

• Fixed size (defined at compile-time)

• Elements must be of the same data type

• Random access using indices

Declaring and Initializing Arrays

#include <iostream>
using namespace std;

int main() {
    // Declaration
    int numbers[5];

    // Initialization
    numbers[0] = 10;
    numbers[1] = 20;
    numbers[2] = 30;
    numbers[3] = 40;
    numbers[4] = 50;

    // Access elements
    for (int i = 0; i < 5; i++) {
        cout << numbers[i] << " ";
    }

    return 0;
}

Output:

10 20 30 40 50

Array Initialization at Declaration

#include <iostream>
using namespace std;

int main() {
    int marks[5] = {90, 85, 78, 92, 88};

    for (int i = 0; i < 5; i++) {
        cout << "Marks[" << i << "] = " << marks[i] << endl;
    }

    return 0;
}

Output:

Marks[0] = 90
Marks[1] = 85
Marks[2] = 78
Marks[3] = 92
Marks[4] = 88

Types of Arrays

• One-Dimensional Array – Simple list of elements

• Two-Dimensional Array (Matrix) – Table-like structure (rows and columns)

• Multi-Dimensional Arrays – Arrays with more than two dimensions

Example – Two-Dimensional Array

#include <iostream>
using namespace std;

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

    for (int i = 0; i < 2; i++) {
        for (int j = 0; j < 3; j++) {
            cout << matrix[i][j] << " ";
        }
        cout << endl;
    }
    return 0;
}

Output:

1 2 3
4 5 6

Advantages of Arrays

• Easy to store and manage large sets of data

• Fast random access using indices

• Contiguous memory allocation improves performance

Limitations of Arrays

• Fixed size (cannot be changed at runtime)

• All elements must be of the same data type

• Insertion and deletion operations are costly

Conclusion

Arrays are a simple yet powerful data structure in C++. They allow you to group multiple values of the same type and access them efficiently using indices. Mastering arrays is essential before learning advanced data structures like vectors and linked lists.