Found 7442 Articles for Java

How to check if ArrayList contains an item in Java?

Vivek Verma
Updated on 19-May-2025 15:27:41

5K+ Views

To check if an ArrayList contains a specific item, we can either compare each element with the given item and print the result if they are equal, or use a predefined method that directly checks for the containing element. ArrayList in Java In Java, an ArrayList is a class similar to an Array, but unlike an array, it has a dynamic size that automatically increases or decreases, depending on the number of elements added or removed from it. Following is the syntax for creating an ArrayList in Java - ArrayList list_name = new ArrayList(); Here, ... Read More

How does a list work in Java?

Mahesh Parahar
Updated on 10-May-2022 08:42:04

208 Views

public interface List extends CollectionThe List interface extends Collection and declares the behavior of a collection that stores a sequence of elements.Elements can be inserted or accessed by their position in the list, using a zero-based index.A list may contain duplicate elements.In addition to the methods defined by Collection, List defines some of its own, which are summarized in the following table.Several of the list methods will throw an UnsupportedOperationException if the collection cannot be modified, and a ClassCastException is generated when one object is incompatible with another.ExampleThe above interface has been implemented in various classes like ArrayList or LinkedList, ... Read More

How do you turn an ArrayList into a Set in Java?

Aishwarya Naglot
Updated on 30-May-2025 18:10:34

11K+ Views

In this article, let's learn how to convert an ArrayList into a Set in Java. ArrayList is a collection that allows us to store duplicates, whereas Set is a collection that does not allow duplicates. So, when we convert an ArrayList to a Set, all the duplicate elements will be removed. If someone tries to add duplicate elements to a Set, it will not throw an error but will simply ignore the duplicate elements. Let's take an example: Input: [1, 2, 3, 4, 5, 5, 6] Output: [1, 2, 3, 4, 5, 6] Ways to Convert an ArrayList to ... Read More

How do you search for an element in an ArrayList in Java?

Aishwarya Naglot
Updated on 30-May-2025 18:29:25

7K+ Views

In this article, we will learn how to search for an element in an ArrayList in Java. ArrayList is an interface that extends another interface called the List interface. It provides a way to store elements and also provides resizable functionality. Let's take an example: Input: [1, 2, 3, 4, 5] Element to search: 3 Output: Element 3 found at index 2 Ways to Search for an Element in an ArrayList Below are the different approaches to searching for an element in an ArrayList: Using indexOf() method Using contains() method Using for loop Using Stream API ... Read More

How do you make a shallow copy of a list in Java?

Aishwarya Naglot
Updated on 30-May-2025 18:35:52

921 Views

In this article, we will learn how to make a shallow copy of a List in Java. What is the List in Java? List is a part of the Java collection framework. It stores elements sequentially and also allows us to store duplicate elements. It is an interface, not a class, so it cannot be instantiated directly. However, there are several classes that implement the List interface, such as ArrayList, LinkedList, and Vector. Shallow Copy of a List A shallow copy means it is a copy of the original list, but elements in the copied list are still referencing the ... Read More

How do you make a list iterator in Java?

Aishwarya Naglot
Updated on 05-Jun-2025 12:29:16

363 Views

List Iterators in Java are mainly useful for traversing a list in both directions (forward and backward). They allow you to iterate through the elements of a list while providing methods to modify the list during iteration. In this article, we will learn how to create or make a list iterator in Java. Ways to Create a List Iterator in Java Using ListIterator Interface Using the Iterator Interface Using Stream API Using ListIterator Interface We can utilize listIterator() method of the List interface, which allows element ... Read More

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

892 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

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