Arrays and Lists in C#, Java, Python and JavaScript

list-examples.js

// List examples in JavaScript

let incomes = [150, 200, 70.50, 120];

// Print the list (naturally)
console.log(incomes);

// Print the list (using foreach loop)
console.log("Incomes:");
for (let x of incomes) {
    console.log(" ", x)
}
console.log();

// Add a new element
incomes.push(300);
console.log("Added 300");
console.log("Incomes:", incomes);
console.log();

// Calculate count, sum, average, first, last, ...
console.log("Count:", incomes.length);
console.log("First:", incomes[0]);
console.log("Second:", incomes[1]);
console.log("Last:", incomes[incomes.length-1]);
console.log("Sum:", incomes.reduce((a,b) => a + b, 0));
console.log("Avg:", incomes.reduce((a,b) => a + b, 0) / incomes.length);
console.log();

// Remove elements at position 1, 2 and 3
incomes.splice(1, 3);
console.log("Deleted 3 elements starting at index 1");
console.log("Incomes:", incomes);
console.log();

// Modify an existing element
incomes[0] = incomes[0] * 1.2;
console.log("Increased the first income with 20%");
console.log("Incomes:", incomes);
console.log();

list-examples.py

# List examples in Python

incomes = [150, 200, 70.50, 120]

# Print the list using a fore-loop
print("Incomes:")
for x in incomes:
    print(" ", x)
print()

# Add a new element
incomes.append(300)
print("Added 300")
print("Incomes:", incomes)
print()

# Calculate count, sum, average, first, last, ...
print("Count:", len(incomes))
print("First:", incomes[0])
print("Second:", incomes[1])
print("Last:", incomes[-1])
print("Sum:", sum(incomes))
print("Avg:", sum(incomes) / len(incomes))
print()

# Remove elements at position 1, 2 and 3
incomes = incomes[:1] + incomes[4:]
print("Deleted 3 elements starting at index 1")
print("Incomes:", incomes)
print()

# Modify an existing element
incomes[0] = incomes[0] * 1.2
print("Increased the first income with 20%")
print("Incomes:", incomes)
print()

ListExamples.cs

// List examples in C#

using System;
using System.Collections.Generic;
using System.Linq;

class ListExamples
{
    static void Main()
    {

        var incomes = new List<double> {
            150, 200, 70.50, 120
        };

        // Print the list using a foreach-loop
        Console.WriteLine("Incomes:");
        foreach (var amount in incomes)
        {
            Console.WriteLine(amount);
        }
        Console.WriteLine();

        // Add a new element
        incomes.Add(300);
        Console.WriteLine("Added 300");

        // Print the list using String.Join()
        Console.WriteLine("Incomes: {0}\n",
            String.Join(", ", incomes));

        // Calculate count, sum, average, first, last, ...
        Console.WriteLine("Count = {0}", incomes.Count);
        Console.WriteLine("First = {0}", incomes.First());
        Console.WriteLine("Second = {0}", incomes.Skip(1).First());
        Console.WriteLine("Last = {0}", incomes.Last());
        Console.WriteLine("Sum = {0}", incomes.Sum());
        Console.WriteLine("Avg = {0}", incomes.Average());
        Console.WriteLine();

        // Remove elements at position 1, 2 and 3
        incomes.RemoveRange(1, 3);
        Console.WriteLine("Deleted 3 elements starting at index 1");

        // Modify an existing element
        incomes[0] = incomes[0] * 1.20;
        Console.WriteLine("Increased the first income with 20%");

        // Print the list using a for-loop
        Console.WriteLine("Incomes:");
        for (var index = 0; index < incomes.Count; index++)
        {
            Console.WriteLine(incomes[index]);
        }
        Console.WriteLine();
    }
}

ListExamples.java

// List examples in Java

import java.util.ArrayList;
import java.util.Arrays;
import java.util.stream.Collectors;

public class ListExamples {
    public static void main(String[] args) {
        var incomes = new ArrayList<Double>(
            Arrays.asList(150.0, 200.0, 70.50, 120.0)
        );

        // Print the list using a foreach-loop
        System.out.println("Incomes:");
        for (var amount : incomes)
            System.out.println(amount);
        System.out.println();

        // Add a new element
        incomes.add(300.0);
        System.out.println("Added 300");

        System.out.println("Incomes: " + incomes);

        // Print the list using Collectors.joining()
        System.out.printf("Incomes: %s\n\n",
                incomes.stream()
                        .map(x -> String.valueOf(x))
                        .collect(Collectors.joining(", ")));

        // Calculate count, sum, average
        System.out.printf("Count = %d\n", incomes.size());
        System.out.printf("First = %s\n", incomes.stream().findFirst().get());
        System.out.printf("First = %s\n", incomes.get(0));
        System.out.printf("Second = %s\n", incomes.stream().skip(1).findFirst().get());
        System.out.printf("Second = %s\n", incomes.get(1));
        System.out.printf("Last = %s\n", incomes.stream().skip(incomes.size() - 1).findFirst().get());
        System.out.printf("Last = %s\n", incomes.get(incomes.size() - 1));
        System.out.printf("Sum = %s\n", incomes.stream().mapToDouble(Number::doubleValue).sum());
        System.out.printf("Avg = %s\n", incomes.stream().mapToDouble(Number::doubleValue).average().getAsDouble());
        System.out.println();

        // Remove elements at position 1, 2 and 3
        incomes.subList(1, 4).clear();
        System.out.println("Deleted 3 elements starting at index 1");
        System.out.println(incomes);

        // Modify an existing element
        incomes.set(0,  incomes.get(0) * 1.20);
        System.out.println("Increased the first income with 20%\n");

        // Print the list using a for-loop
        System.out.println("Incomes:");
        for (var i = 0; i < incomes.size(); i++)
            System.out.println(incomes.get(i));
        System.out.println();
    }
}