To insert a node in between a linked list, we need to first break the existing link and then create two new links. It will be clear from the picture given below. Point the ‘next’ of the new node to the node ‘b’ (the node after which we have to insert the new node).

make the last node => next as the new node.

1. Declare head pointer and make it as NULL. struct node { int data; struct node *next; }; struct node *head = NULL;
2. Create a new node.
3. If the head node is NULL, make the new node as head.
4. Otherwise, find the last node and set last node => new node.

Algorithm

1. Define a Node class which represents a node in the list.
2. Define another class for creating a doubly linked list, and it has two nodes: head and tail.
3. addNode() will add node to the list:
4. countNodes() will count the number of nodes present in the list.
5. display() will show all the nodes present in the list.

Each record of a linked list is often called an ‘element’ or ‘node’. The field of each node that contains the address of the next node is usually called the ‘next link’ or ‘next pointer’.

There are three common types of Linked List.

• Singly Linked List.
• Doubly Linked List.
• Circular Linked List.

Linked lists also use more storage space in a computer’s memory as each node in the list contains both a data item and a reference to the next node. It follows that linked lists should be used for large lists of data where the total number of items in the list is changing.

Adding or removing elements is a lot faster in a linked list than in an array. Iterating sequentially over the list one by one is more or less the same speed in a linked list and an array. Getting one specific element in the middle is a lot faster in an array.

An array is a collection of elements of a similar data type. Linked List is an ordered collection of elements of the same type in which each element is connected to the next using pointers. Array elements can be accessed randomly using the array index. Random accessing is not possible in linked lists.

Conclusion: LinkedList element deletion is faster compared to ArrayList. Reason: LinkedList’s each element maintains two pointers (addresses) which points to the both neighbor elements in the list. 3) Inserts Performance: LinkedList add method gives O(1) performance while ArrayList gives O(n) in worst case.

An array stores a fixed-size sequential collection of elements of the same type, whereas list is a generic collection.

Each element (we will call it a node) of a list is comprising of two items – the data and a reference to the next node. The last node has a reference to null. The entry point into a linked list is called the headof the list. It should be noted that head is not a separate node, but the reference to the first node.

Better use of Memory: From a memory allocation point of view, linked lists are more efficient than arrays. Unlike arrays, the size for a linked list is not pre-defined, allowing the linked list to increase or decrease in size as the program runs.

Linked lists are preferable over arrays when:

1. you need constant-time insertions/deletions from the list (such as in real-time computing where time predictability is absolutely critical)
2. you don’t know how many items will be in the list.
3. you don’t need random access to any elements.

Linked lists differ from lists in the way that they store elements in memory. While lists use a contiguous memory block to store references to their data, linked lists store references as part of their own elements.

Both ArrayList and LinkedList are implementation of List interface in Java. Both classes are non-synchronized. ArrayList internally uses a dynamic array to store its elements. LinkedList uses Doubly Linked List to store its elements.

What operation is least efficient in a LinkedList? Random access of an element.

A linked list is a linear data structure where each element is a separate object. Each element (we will call it a node) of a list is comprising of two items – the data and a reference to the next node. The last node has a reference to null. The entry point into a linked list is called the head of the list.

Singly linked list allows traversal elements only in one way. Doubly linked list allows element two way traversal. On other hand doubly linked list can be used to implement stacks as well as heaps and binary trees. On other hand Doubly linked list uses more memory per node(two pointers).

What type of edge does UML use to denote interface implementation? A dotted arrow from the class to the interface terminated with a triangular tip.

Answer and Explanation: The only true statement is C), All methods defined in an interface must be implemented when used by another class.

An interface can contain properties, methods and events. The keyword must implement forces implementation of an interface. Interfaces can be overloaded. Interfaces can be implemented by a class or a struct.

Similar to Default Method in Interface, the static method in an interface can be defined in the interface, but cannot be overridden in Implementation Classes. To use a static method, Interface name should be instantiated with it, as it is a part of the Interface only.

Which of the following statements is correct about an interface?

Java programmers commonly define constants inside their interfaces, if it makes design sense. You can do so using variables in an interface because the values will be present instantly at runtime and their values shared among all classes implementing your interface, because they are static and final.

An interface is declared by using the interface keyword. It provides total abstraction; means all the methods in an interface are declared with the empty body, and all the fields are public, static and final by default. A class that implements an interface must implement all the methods declared in the interface.

A class implements two interfaces each containing three methods….Exercise :: Interfaces – General Questions.