Implement Arrays in different Programming Languages

Arrays are one of the basic data structures that should be learnt by every programmer. Arrays stores a collection of elements, each identified by an index or a key. They provide a way to organize and access a fixed-size sequential collection of elements of the same type. In this article, we will learn about the basic use of array in most common languages like C, C++, Java, Python, etc.

What is an Array?

Arrays are data structures that store collections of elements in contiguous memory locations. Each element is identified by an index or key, allowing for efficient random access. Arrays offer advantages like constant-time access and memory efficiency. However, they have disadvantages such as a fixed size and inefficient insertion/deletion.

Implementation of array in C++:

• Declares an integer array arr with a size of 5 and initializes it with values.
• Accesses the element at index 3 using arr[3] and prints its value.
• Modifies the element at index 3 by assigning a new value (15) to arr[3] and prints the modified value.

C++

#include <iostream>
using namespace std;

int main() {
    int arr[5] = {1, 2, 3, 4, 5};  // Initialize an array

    // Access elements
    cout << "Element at index 3: " << arr[3] << endl;

    // Modify elements
    arr[3] = 15;
    cout << "Modified element at index 3: " << arr[3] << endl;

    return 0;
}

Output

Element at index 3: 4
Modified element at index 3: 15

Implementation of array in C:

• Declares an integer array arr with a size of 5 and initializes it with values.
• Accesses the element at index 2 using arr[2] and prints its value.
• Modifies the element at index 2 by assigning a new value (10) to arr[2] and prints the modified value.

C

#include <stdio.h>

int main() {
    int arr[5] = {1, 2, 3, 4, 5};  // Initializing an array with values

    // Accessing elements
    printf("Element at index 2: %d\n", arr[2]);

    // Modifying elements
    arr[2] = 10;
    printf("Modified element at index 2: %d\n", arr[2]);

    return 0;
}

Output

Element at index 2: 3
Modified element at index 2: 10

Implementation of array in Java:

• Declares an integer array arr and initializes it with values using the array initializer syntax.
• Accesses the element at index 4 using arr[4] and prints its value.
• Modifies the element at index 4 by assigning a new value (20) to arr[4] and prints the modified value.

Java

public class Main {
    public static void main(String[] args) {
        int[] arr = {1, 2, 3, 4, 5};  // Initializing an array with values

        // Accessing elements
        System.out.println("Element at index 4: " + arr[4]);

        // Modifying elements
        arr[4] = 20;
        System.out.println("Modified element at index 4: " + arr[4]);
    }
}

Javascript

class Main {
    static main() {
        const arr = [1, 2, 3, 4, 5];  // Initializing an array with values

        // Accessing elements
        console.log("Element at index 4: " + arr[4]);

        // Modifying elements
        arr[4] = 20;
        console.log("Modified element at index 4: " + arr[4]);
    }
}

// Call the main method
Main.main();

Output

Element at index 4: 5
Modified element at index 4: 20

Implementation of array in Python:

• Initializes a Python list arr with values.
• Accesses the element at index 1 using arr[1] and prints its value.
• Modifies the element at index 1 by assigning a new value (12) to arr[1] and prints the modified value.

Python3

arr = [1, 2, 3, 4, 5]  # Initializing an array with values

# Accessing elements
print("Element at index 1:", arr[1])

# Modifying elements
arr[1] = 12
print("Modified element at index 1:", arr[1])

Output

Element at index 1: 2
Modified element at index 1: 12

Implementation of array in C#:

• Declares an integer array arr and initializes it with values using the new keyword.
• Accesses the element at index 0 using arr[0] and prints its value.
• Modifies the element at index 0 by assigning a new value (8) to arr[0] and prints the modified value.

C#

using System;

class Program {
    static void Main() {
        int[] arr = new int[] {1, 2, 3, 4, 5};  // Initializing an array with values

        // Accessing elements
        Console.WriteLine("Element at index 0: " + arr[0]);

        // Modifying elements
        arr[0] = 8;
        Console.WriteLine("Modified element at index 0: " + arr[0]);
    }
}

Output

Element at index 0: 1
Modified element at index 0: 8

Implementation of array in JavaScript:

• Initializes a JavaScript array arr with values.
• Accesses the element at index 0 using arr[0] and prints its value.
• Modifies the element at index 0 by assigning a new value (9) to arr[0] and prints the modified value.

Javascript

let arr = [1, 2, 3, 4, 5];  // Initializing an array with values

// Accessing elements
console.log("Element at index 0:", arr[0]);

// Modifying elements
arr[0] = 9;
console.log("Modified element at index 0:", arr[0]);

Output

Element at index 0: 1
Modified element at index 0: 9

Pros and Cons of array:

Pros of Arrays	Cons of Arrays
1. Allows direct access using index, facilitating quick retrieval.	1. Set size is not easily changeable, limiting adaptability.
2. Minimizes memory overhead by storing elements in contiguous memory locations.	2. Inefficient when adding/removing elements in the middle.
3. Supports easy iteration, simplifying the process with loops.	3. Wasted memory if the array is larger than needed.
4. Constant-time access provides predictable and consistent performance.	4. Elements must be stored in order, restricting memory allocation.
5. Facilitates efficient algorithm and data structure implementations.	5. Limited flexibility as arrays typically holds one data type.