Iterate Through Elements of LinkedHashSet in Java

Java Program to Iterate LinkedHashSet Elements

The LinkedHashSet is an ordered version of HashSet that maintains a doubly-linked List across all elements. When the iteration order is needed to be maintained this class is used.

Example:

Input: 
["Beginner", "for", "Beginner"]


Output:
Beginner
for
Beginner
    
Input: 
[9, 4, 6, 2, 8]


Output:
9
4
6
2
8

Different Ways to Iterate LinkedHashSet Elements:

Using the for-each loop
Using iterators
Using JDK 1.8 streams

Method 1: Using the for-each loop

Java

// Java Program to Iterate through linkedHashset 
// Using the for-each loop 
  
import java.io.*; 
import java.util.LinkedHashSet; 
  
class GFG { 
    public static void main(String[] args) 
    { 
  
        LinkedHashSet<String> gfg 
            = new LinkedHashSet<String>(); 
  
        // Adding element to LinkedHashSet 
        gfg.add("Beginner"); 
        gfg.add("for"); 
        gfg.add("Beginner"); 
  
        // iterating LinkedHashSet using enhanced for loop 
        for (String itr : gfg) { 
            System.out.println(itr); 
        } 
    } 
}

Output

Beginner
for
Beginner

Method 2: Using iterators

Iterate through the elements of LinkedHashSet using the iterator method. We will use the hasNext() method and the next() method along with the while loop to iterate through LinkedHashSet elements.

Type Parameters:

E – the type of elements maintained by this set.

Syntax:

public Iterator<E> iterator()

Return: This method returns the element of LinkedHashSet in the same order as the input.

Java

// Java code to demonstrate  
// the iterating over LinkedHashSet  
// Using iterators 
    
import java.io.*;  
import java.util.*;  
    
class IteratingLinkedHashSet {  
    
    public static void main(String[] args)  
    {  
        // Instantiate an object of Set  
        // Since LinkedHashSet implements Set  
        // Set points to LinkedHashSet  
        Set<String> gfg = new LinkedHashSet<String>();  
    
        // Elements are added using add() method  
        gfg.add("Geek");  
        gfg.add("For");  
        gfg.add("Beginner");  
        gfg.add("Courses");  
        gfg.add("Interview Prep");  
        gfg.add("Doubt Classes");  
    
        // Iterating through the LinkedHashSet  
        Iterator itr = gfg.iterator();  
        
        while (itr.hasNext()){ 
              System.out.println( itr.next() ); 
        } 
    } 
}

Output

Geek
For
Beginner
Courses
Interview Prep
Doubt Classes

Method 3: Using JDK 1.8 streams

Iterate through the elements of LinkedHashSet using the forEach method. We will iterate through the entire content using Stream. The stream represents a sequence of objects from a source, which supports aggregate operations.

Syntax:

set.stream().forEach()

Return: Returns a sequential stream considering collection as its source.

Java

// Java code to demonstrate 
// the iterating over LinkedHashSet 
// Using JDK 1.8 streams 
  
import java.io.*; 
import java.util.*; 
  
class GFG { 
    public static void main(String[] args) 
    { 
  
        LinkedHashSet<Integer> gfg = new LinkedHashSet<Integer>(); 
  
        // Elements are added using add() method 
        gfg.add(9); 
        gfg.add(7); 
        gfg.add(11); 
        gfg.add(43); 
        gfg.add(2); 
  
        // Using forEach Method using Stream. 
        gfg.stream().forEach(System.out::println); 
    } 
}

Output

Time complexity: O(N), where N is no. of elements of LinkedHashSet.

Tags:

#Java-Collections #java-LinkedHashSet #Technical Scripter 2020 #Java #Java Programs #Technical Scripter #Java #Java-Collections

Java Program to Iterate LinkedHashSet Elements

Iterate Through Elements of LinkedHashSet in Java

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