In this tutorial we will learn about How to convert java array to Set . We will discuss how to convert array to Set in java using constructor , set.addAll() method , Collections.addAll() method and loop over array .Please Don’t use duplicate elements in the array, because duplicates will be discarded in the set.
Convert array to Set In Java
Now we will see different approaches for how to convert array to Set in java.
1. Java Array to Set using TreeSet Constructor
In this example we will create a array of Strings. Now we will initialize TreeSet Using Parameterized Constructor with the array (arr) elements .
import java.util.Arrays;
import java.util.Set;
import java.util.TreeSet;
public class ArrayToSet {
public static void main(String[] args) {
//create array of Strings
String [] arr={"java","vogue","welcomes"};
for (String element : arr) {
System.out.println("Array element is : "+element);
}
//initialize Set using array elements
Set<String> set = new TreeSet<String>(Arrays.asList(arr));
// print TreeSet Element
System.out.println("Set Elements : "+ set);
}
}
Output:
Array element is : java
Array element is : vogue
Array element is : welcomes
Set Elements : [java, vogue, welcomes]
2. Convert Array to Set using Set.addAll() method
In this example we will convert array to Set in java using addAll() method of Set . Firstly we created array (arr) of Strings .Now we will create Set , then add array elements to it using Set.addAll() method . Let,s see java program add array element to set in java.
import java.util.Arrays;
import java.util.Set;
import java.util.TreeSet;
public class ArrayToSet1 {
public static void main(String[] args) {
// create array of Strings
String[] arr = { "java", "vogue", "welcomes" };
for (String element : arr) {
System.out.println("Array element is : " + element);
}
Set<String> set = new TreeSet<String>();
//adding arr elements to the Set using the addAll() method
set.addAll(Arrays.asList(arr));
// print TreeSet Element
System.out.println("Set Elements : " + set);
}
}
Output:
Array element is : java
Array element is : vogue
Array element is : welcomes
Set Elements : [java, vogue, welcomes]
3. Java Array to Set using Collections.addAll() method
We can convert array to Set in java using Collections.addAll() method. We created array (arr) of Strings firstly .Now We will create Set , then add array elements to it using Collections.addAll() method .
import java.util.Collections;
import java.util.Set;
import java.util.TreeSet;
public class ArrayToSet2 {
public static void main(String[] args) {
// create array of Strings
String[] arr = { "java", "vogue", "welcomes" };
for (String element : arr) {
System.out.println("Array element is : " + element);
}
Set<String> set = new TreeSet<String>();
//adding elements of array to Set using Collections.addAll() method
Collections.addAll(set, arr);
// print TreeSet Element
System.out.println("Set Elements : " + set);
}
}
Output:
Array element is : java
Array element is : vogue
Array element is : welcomes
Set Elements : [java, vogue, welcomes]
4. Convert Array to Set Using add() Method
In this approach,we will convert array (arr) to Set in java using for loop . We create array of Strings and add some elements into it. We also created one Set. Now We Iterate array (arr) element Using for-each loop and one by one element of array(arr) will added to Set using add() method . Let,s see java program for this approach.
import java.util.Set;
import java.util.TreeSet;
public class ArrayToSet3 {
public static void main(String[] args) {
// create array of Strings
String[] arr = { "java", "vogue", "welcomes" };
for (String element : arr) {
System.out.println("Array element is : " + element);
}
Set<String> set = new TreeSet<String>();
for (String element : arr) {
//add element from array to Set
set.add(element);
}
// print TreeSet Element
System.out.println("Set Elements : " + set);
}
}
Output:
Array element is : java
Array element is : vogue
Array element is : welcomes
Set Elements : [java, vogue, welcomes]
In this tutorial we have learned java array to set conversion using different approaches . You can see more java TreeSet Program for practice .
References :