## 10 Basic Data Structure Interview Questions and Answers

**What is Data Structure?**

Data Structure is organization of data in such a way that manipulation and operations over the data can be done easily. There are many ways to achieve this goal. We have two broad category as Linear and Non-Linear.Data structure is equally useful in analyzing complexity of heavy applications running over huge traffic and data.

**What is linear and Non linear data structures?**

Linear Data Structures are the structures where data is arranged in sequential manner and can be add or delete in a sequence. But not leaner is fashion to arrange data in non sequential manner. We can random add or delete data from the structure.

**What is an Array?**

Array is a Linear type Data Structure which is used to collect similar type of elements and stored in contiguous in memory locations identified by index. Index of array starts from zero(0). We can randomly access the element of array using these indices.

**What is a Stack?**

Stack is an ordered collection of elements where addition and removal of elements are happens at the same end. Such type of arrangement called LIFO, last-in first-out.A linked list is Suitable for operations such as add, delete, and update.There are two elementary operations performed on Stacks

1-push : add a new element at the top of the stack

2-pop : remove the top element fro the top of the stack

**What is a Linked List?**

A Data structure where elements are connected via links. Links contains Items and reference to another links. There are three types of Linked lists:

1-Simple Linked List

2-Double Linked List

3-Circular Linked List

**What is Queue?**

A Queue is a Data Structure opened at its ends. One end is open to insert new items in queue and another is open to release existing items for queue. The basic operations of enqueue() and dequeue() work in FIFO- First In First Out Fashion. enqueue() is used to add new items in queue where as dequeue() is used to remove existing items from queue.

**How many types of Linked List are there?**

There are three types of Linked lists:

1-Simple Linked List

2-Double Linked List

3-Circular Linked List

**What is a Tree?**

A tree is collection of nodes connected to each other and in a hirerarchy to maintain parent and child type relation ship.A tree is a nonlinear data structure.There is a root node and next nodes are connected to root by directed edges and so on.A tree without node is empty tree. Parent->Children.

**What is a Heap?**

A heap is a Non Linear Data Structure based on tree and containing properties of Heap.

**What is a Graph?**

Collection of Nodes arranged as vertices and edges known as Graph. Graph is a Non Linear type Data Structure.The relationship found between vertices is known as adjacency.