Lists, Sets, and Maps

Topic

Java Exercise

In this exercise, you will create a Java program that demonstrates the use of **Lists**, **Sets**, and **Maps**. First, you will create a **List** to store an ordered collection of items, a **Set** to store single, unordered items, and a **Map** to associate keys with values. Next, you will implement operations such as adding, deleting, accessing, and searching for and modifying items in these collections. This exercise will help you understand how and when to use these data structures in a Java program.

Instructions:

1. Create a **List** of type ArrayList and add several elements to the list.
2. Create a **Set** of type HashSet and add elements, ensuring there are no duplicates.
3. Create a **Map** of type HashMap and associate several keys with their respective values.
4. Perform delete, search, and modify operations on each of the collections.
5. Print the contents of each collection to show how the elements have been manipulated.

This exercise will help you understand how **Lists**, **Sets**, and **Maps** are used in Java to efficiently store and manipulate data, and How to choose the right structure for your program's needs.

import java.util.ArrayList;
import java.util.HashSet;
import java.util.HashMap;

public class CollectionExercise {
    public static void main(String[] args) {
        // List
        ArrayList<String> list = new ArrayList<>();
        list.add("Apple");
        list.add("Banana");
        list.add("Cherry");

        // Set
        HashSet<String> set = new HashSet<>();
        set.add("Red");
        set.add("Green");
        set.add("Blue");

        // Map
        HashMap<String, String> map = new HashMap<>();
        map.put("First Name", "John");
        map.put("Last Name", "Doe");
        map.put("Age", "30");

        // Display List
        System.out.println("List: " + list);

        // Display Set
        System.out.println("Set: " + set);

        // Display Map
        System.out.println("Map: " + map);
    }
}

List: [Apple, Banana, Cherry]
Set: [Red, Green, Blue]
Map: {First Name=John, Last Name=Doe, Age=30}