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Understanding the Collection.removeIf Method

Understanding the Collection.removeIf Method

Collection.removeIf is a very powerful method that acts on a condition. In the code sample below, there is a list which has few elements in it and the condition is to list all elements that are not even numbers. The condition is specified in the Predicate.

Code snippet:

import java.util.function.Predicate;import java.util.*;public class CollectionsRemoveIf{   public static void main(String args[])   {      CollectionsRemoveIf collectionsRemoveIf = new CollectionsRemoveIf();      collectionsRemoveIf.proceed();   }      private void proceed()   {      List numbers = new ArrayList();      numbers.add(1);      numbers.add(3);      numbers.add(5);      numbers.add(6);      numbers.add(7);      numbers.add(8);            Predicate removeEvenNumbers = i - i % 2 == 0;      System.out.println("Original list...");      for (int numberValue : numbers) {         System.out.println(numberValue);      }                  //Predicate, the condition, is being added to the removeIf.      numbers.removeIf(removeEvenNumbers);            System.out.println("Odd numbers list...");      for (int numberValue : numbers) {         System.out.println(numberValue);      }         }}/*

Expected output:

[root@mypc]# java CollectionsRemoveIfOriginal list...135678Odd numbers list...1357*/
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