1. Introduction

In Java, a Set is a collection that does not allow duplicate elements. Iterating over a Set is a common task that enables developers to access and operate on each element. This guide will demonstrate various methods to iterate through a Set in Java, including using an enhanced for loop, iterator, and Java 8 forEach method.

2. Program Steps

1. Import the necessary libraries.

2. Create and initialize a Set.

3. Use different methods to iterate over the set.

4. Output the elements of the set.

3. Code Program

// Step 1: Import the necessary libraries
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

public class SetIteration {

    public static void main(String[] args) {

        // Step 2: Create and initialize a Set
        Set<String> fruitSet = new HashSet<>();
        fruitSet.add("Apple");
        fruitSet.add("Banana");
        fruitSet.add("Cherry");
        fruitSet.add("Date");

        // Step 3: Use different methods to iterate over the set

        // Using enhanced for loop
        System.out.println("Using enhanced for loop:");
        for (String fruit : fruitSet) {
            System.out.println(fruit);
        }

        // Using iterator
        System.out.println("Using iterator:");
        Iterator<String> iterator = fruitSet.iterator();
        while (iterator.hasNext()) {
            System.out.println(iterator.next());
        }

        // Using forEach method with lambda expression
        System.out.println("Using forEach with lambda:");
        fruitSet.forEach(fruit -> System.out.println(fruit));
    }
}

Output:

Using enhanced for loop:
Apple
Banana
Cherry
Date
Using iterator:
Apple
Banana
Cherry
Date
Using forEach with lambda:
Apple
Banana
Cherry
Date

4. Step By Step Explanation

Step 1: Start by importing the necessary libraries. In this program, we use Set, HashSet, and Iterator.

Step 2: Create and initialize a Set with some elements.

Step 3: Three different methods are used to iterate over the set.

– First, we use an enhanced for loop, which is a simple and concise way to traverse each element.

– Second, we utilize an Iterator that offers a way to access the elements of a collection sequentially.

– Lastly, we apply the forEach method with a lambda expression, a functional approach introduced in Java 8.

Step 4: In each iteration method, print out the elements of the set.