How to remove duplicates from ArrayList in Java?

Answer 1

To remove dupliates from ArrayList, we can convert it into Set. Since Set doesn't contain duplicate elements, it will have only unique elements.

Let's see an example to remove duplicates from ArrayList:

public class RemoveDuplicateArrayList {   
    public static void main(String[] args) {  
        List<String> l = new ArrayList<String>();  
        l.add("Mango");  
        l.add("Banana");  
        l.add("Mango");  
        l.add("Apple");  
        System.out.println(l.toString());  
        Set<String> s = new LinkedHashSet<String>(l);  
        System.out.println(s);  
    }  
}  

Output:

Before converting to set
[Mango, Banana, Mango, Apple]
After converting to set
[Mango, Banana, Apple]