CopyOnWriteArrayList isEmpty() method in Java Last Updated : 26 Nov, 2018 Summarize Comments Improve Suggest changes Share Like Article Like Report The isEmpty(E e) method of CopyOnWriteArrayList checks if the list is empty or not. It returns true if the list is empty, else it returns false. Syntax: public boolean isEmpty() Parameters: The function does not accepts any parameter. Return Value: The function returns true if the list is empty, otherwise it returns false. Below programs illustrate the above function: Program 1: Java // Java Program to illustrate the // isEmpty() method in Java import java.util.concurrent.CopyOnWriteArrayList; import java.util.*; public class GFG { public static void main(String[] args) { // create object of CopyOnWriteArrayList CopyOnWriteArrayList<Integer> ArrLis = new CopyOnWriteArrayList<Integer>(); // Add elements ArrLis.add(32); ArrLis.add(67); ArrLis.add(98); ArrLis.add(100); // print CopyOnWriteArrayList System.out.println("CopyOnWriteArrayList: " + ArrLis); // check using function if (ArrLis.isEmpty()) System.out.println("List is empty"); else System.out.println("List is not empty"); ArrLis.clear(); // check using function if (ArrLis.isEmpty()) System.out.println("List is empty"); else System.out.println("List is not empty"); } } Output: CopyOnWriteArrayList: [32, 67, 98, 100] List is not empty List is empty Program 2: Java // Java Program to illustrate the // isEmpty() method in Java import java.util.concurrent.CopyOnWriteArrayList; import java.util.*; public class GFG { public static void main(String[] args) { // create object of CopyOnWriteArrayList CopyOnWriteArrayList<String> ArrLis = new CopyOnWriteArrayList<String>(); // Add elements ArrLis.add("gopal"); ArrLis.add("gfg"); ArrLis.add("jgec"); ArrLis.add("sudo"); // print CopyOnWriteArrayList System.out.println("CopyOnWriteArrayList: " + ArrLis); // check using function if (ArrLis.isEmpty()) System.out.println("List is empty"); else System.out.println("List is not empty"); ArrLis.clear(); // check using function if (ArrLis.isEmpty()) System.out.println("List is empty"); else System.out.println("List is not empty"); } } Output: CopyOnWriteArrayList: [gopal, gfg, jgec, sudo] List is not empty List is empty Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/CopyOnWriteArrayList.html#isEmpty-- Comment More infoAdvertise with us Next Article CopyOnWriteArrayList isEmpty() method in Java G gopaldave Follow Improve Article Tags : Misc Java Java-Collections Java - util package Java-Functions Java-CopyOnWriteArrayList +2 More Practice Tags : JavaJava-CollectionsMisc Similar Reads CopyOnWriteArraySet isEmpty() method in Java The isEmpty(E e) method of CopyOnWriteArraySet checks if the Set is empty or not. It returns true if the Set is empty, else it returns false. Syntax: public boolean isEmpty() Return Value: The function returns true if the Set is empty, otherwise it returns false. Below programs illustrate the above 1 min read CopyOnWriteArrayList iterator() method in Java The iterator() method of CopyOnWriteArrayList returns an iterator over the elements in this list in proper sequence. The iterator does NOT support the remove method. Syntax: public Iterator iterator() Parameters: The function does not accept any parameters. Return Value: The function returns an iter 2 min read CopyOnWriteArrayList indexOf() method in Java The indexOf(Object o) method of CopyOnWriteArrayList returns the first occurrence of the element passed in the list. It returns -1 if the element is not present in the list. Syntax: public int indexOf(Object o) Parameters: The function accepts a parameter o whose first occurrence is to be returned. 3 min read CopyOnWriteArraySet iterator() method in Java The iterator() method of CopyOnWriteArraySet returns an iterator over the elements in this Set in proper sequence. The iterator does NOT support the remove method. Syntax: public Iterator iterator() Return Value: The function returns an iterator over the elements in the Set. Below programs illustrat 2 min read CopyOnWriteArrayList add() method in Java The add(E e) method of CopyOnWriteArrayList inserts the element passed in the parameter to the end of the List or at a specified index in the list. The function returns true on addition of new element to the list. Syntax: public boolean add(E e) or public void add(int index, E element) Parameters: T 2 min read Like