Found 9150 Articles for Object Oriented Programming

How do you get the index of an element in a list in Java?

Aishwarya Naglot
Updated on 05-Jun-2025 12:36:24

21K+ Views

List is a collection in Java that allows us to store elements. In this article, we will learn how to get the index of an element in a List in Java. We have various ways to get the index of an element in a List in Java. They are - Using the indexOf() method Using a for loop Using Stream API Using the indexOf() method The indexOf() method returns the index of the first occurrence of the specified element in this list, or -1 if this ... Read More

How do you find the element of a LinkedList in Java?

Aishwarya Naglot
Updated on 05-Jun-2025 13:32:16

1K+ Views

A Linked list is a linear type of data structure that is used to store a group of elements. It is a part of the Java Collections Framework. A LinkedList is made up of nodes, where each node contains a data field and a reference to the next node in the sequence. In this article, we will learn how to find an element in a LinkedList in Java. Ways to Find an Element in a LinkedList There are various ways to find an element in a LinkedList in Java. They are - Using the contains() ... Read More

How do you create an empty list in Java?

Aishwarya Naglot
Updated on 05-Jun-2025 12:03:59

53K+ Views

A list is an ordered collection that holds a sequence of elements. In Java, a list is represented by the List Interface of the java.util package. This provides various methods to maintain and manipulate the list.To create a list, you need to instantiate any of the implementing classes of this interface, suchas, ArrayList, LinkedList, Stack, Vector, etc. We can create a List of elements in multiple ways - Without specifying the type Using ArrayList Let's explore these methods in detail. Without specifying the "type" We can create a List without specifying ... Read More

How do you create a list with values in Java?

Aishwarya Naglot
Updated on 05-Jun-2025 14:14:10

893 Views

A List is a Collection in Java that is used for storing elements in sequence. In this article, we will be learning how to create a list with values in Java. Ways to Create a List with Values in Java There are various ways to create a list with values in Java. Below are the different approaches: Using Arrays.asList() method Using Stream.of() method Using List.of() method Using Arrays.asList() method The Arrays.asList() method returns the elements of the current array in the form of a List.  This method ... Read More

How do you create a list in Java?

Mahesh Parahar
Updated on 10-May-2022 07:58:41

8K+ Views

A List of elements can be created using multiple ways.Way #1Create a List without specifying the type of elements it can holds. Compiler will throw warning message for it.List list = new ArrayList();Create a List and specify the type of elements it can holds.Way #2List list = new ArrayList();Way #3Create and initialize the list in one line.List list = Arrays.asList(object1, object 2);ExampleFollowing is the example to explain the creation of List objects −package com.tutorialspoint; import java.util.*; public class CollectionsDemo {    public static void main(String[] args) {       List list = new ArrayList();       list.add("Zara"); ... Read More

How do you create a list from a set in Java?

Mahesh Parahar
Updated on 10-May-2022 07:55:19

287 Views

We can create a list from a set using its constructor.List list = new ArrayList(set);ExampleFollowing is the example showing the conversion of set to list −package com.tutorialspoint; import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Set; public class CollectionsDemo {    public static void main(String[] args) {       Set set = new HashSet();       set.add(1);       set.add(2);       set.add(3);       set.add(4);       System.out.println("Set: " + set);       List list = new ArrayList(set);       System.out.println("List: " + list);    } }OutputThis will produce the following result −Set: [1, 2, 3, 4] List: [1, 2, 3, 4]

How do you copy an element from one list to another in Java?

Mahesh Parahar
Updated on 10-May-2022 07:52:50

824 Views

An element can be copied to another List using streams easily.Use Streams to copy selective elements.List copyOfList = list.stream().filter(i -> i % 2 == 0).collect(Collectors.toList());ExampleFollowing is the example to copy only even numbers from a list −package com.tutorialspoint; import java.util.Arrays; import java.util.List; import java.util.stream.Collectors; public class CollectionsDemo {    public static void main(String[] args) {       List list = Arrays.asList(11, 22, 3, 48, 57);       System.out.println("Source: " + list);       List evenNumberList = list.stream().filter(i -> i % 2 == 0).collect(Collectors.toList());       System.out.println("Even numbers in the list: " + evenNumberList);   ... Read More

How do you check if an element is present in a list in Java?

Mahesh Parahar
Updated on 10-May-2022 07:40:10

6K+ Views

Elements can be checked from a list using indexOf() or contains() methods.Syntax - indexOf() methodint indexOf(Object o)Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element. More formally, returns the lowest index i such that (o==null ? get(i)==null : o.equals(get(i))), or -1 if there is no such index.Parameterso − Element to search for.ReturnsThe index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.ThrowsClassCastException − If the type of the specified element is incompatible with ... Read More

How do you check a list contains an item in Java?

Mahesh Parahar
Updated on 10-May-2022 07:30:39

12K+ Views

Elements can be checked from a list using indexOf() or contains() methods.Syntax - indexOf() methodint indexOf(Object o)Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element. More formally, returns the lowest index i such that (o==null ? get(i)==null : o.equals(get(i))), or -1 if there is no such index.Parameterso − Element to search for.ReturnsThe index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.ThrowsClassCastException − If the type of the specified element is incompatible with ... Read More

How do you add two lists in Java?

Mahesh Parahar
Updated on 10-May-2022 07:24:24

1K+ Views

We can use addAll() methods of List to add two lists.Use addAll() method without index parameterboolean addAll(Collection

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