Java set duplicates

Reading a little into your question I'm guessing that you're seeing strange behaviour with a java. Is it possible to allow duplicate values in the Set collection? In the case of HashMap , it replaces the old value with the new one.

The first thing you need to know is that HashSet acts like a Set , which means you add your object directly to the HashSet and it cannot . This collections Java tutorial describes interfaces, implementations, and algorithms in the Java. A Set is a Collection that cannot contain duplicate elements. Set, it is actually defined as using the equals() method to determine duplicates.

TreeSet class does not use the method . Do you want to identify duplicates elements from Java List? The add method of Set returns false if you try to add a duplicate element. Below example shows how to avoid duplicate user defined objects from HashSet.

How to copy Set content to another HashSet? A Java example to show you how to count the total number of duplicated. Removing the duplicate elements from a List with the standard Java Collections Framework is done easily through a Set: ? So that there is no duplicate element in set.

So in java if we want to add elements in the set then we write code like this.

Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified. That is, if multiple elements are equal, all except . This Java example removes duplicate elements from an ArrayList containing Strings. It uses a HashSet in the removeDuplicates method. All you need to know is that Set doesn't allow duplicates in Java.

Which means if you have added an element into Set and trying to insert . Here's a guide for selecting the proper implementation of a Set, List, or Map. A collection that contains no duplicate elements. More formally, sets contain no pair of elements eand esuch that e1.