## Can you implement stack using ArrayList?

Stack follows LIFO ie., Last In First Out. In this data structure the elements are arranged in such a way that the last element added will be the first one to pop out of it. push – To push the elements(Objects) into the Stack. …

## How would you implement a stack using arrays and generics in Java?

How to Implement Stack in Java Using Array and Generics?

- push() Method adds element x to the stack.
- pop() Method removes the last element of the stack.
- top() Method returns the last element of the stack.
- empty() Method returns whether the stack is empty or not.

**How will you implement a queue using a ArrayList?**

To implement a queue using array, create an array arr of size n and take two variables front and rear both of which will be initialized to 0 which means the queue is currently empty. Element rear is the index upto which the elements are stored in the array and front is the index of the first element of the array.

**How do you implement an ArrayList?**

Consider the below example:

- import java. util. *;
- public class ALExample {
- public static void main(String[] args) {
- List l = new ArrayList<>(); //List Implementation.
- l. add(“Sam”); //adding objects to list.
- l. add(“Sandy”);
- l. add(“Joe”);
- l. add(“Arya”);

### How stack is implemented in Java?

Stack Implementation in Java

- push inserts an item at the top of the stack (i.e., above its current top element).
- pop removes the object at the top of the stack and returns that object from the function.
- isEmpty tests if the stack is empty or not.
- isFull tests if the stack is full or not.

### How do you implement a stack using an array?

There are two ways to implement a stack: Using array. Using linked list….Mainly the following three basic operations are performed in the stack:

- Push: Adds an item in the stack.
- Pop: Removes an item from the stack.
- Peek or Top: Returns the top element of the stack.

**Can we implement queue using stack?**

A queue can be implemented using two stacks. Let queue to be implemented be q and stacks used to implement q be stack1 and stack2. Method 1 (By making enQueue operation costly) This method makes sure that oldest entered element is always at the top of stack 1, so that deQueue operation just pops from stack1.

**How would you implement stack of queues?**

To construct a stack using two queues (q1, q2), we need to simulate the stack operations by using queue operations:

- push (E element) if q1 is empty, enqueue E to q1. if q1 is not empty, enqueue all elements from q1 to q2, then enqueue E to q1, and enqueue all elements from q2 back to q1.
- pop. dequeue an element from q1.

#### How do you implement a List?

Let’s see a simple example of List where we are using the ArrayList class as the implementation.

- import java.util.*;
- public class ListExample1{
- public static void main(String args[]){
- //Creating a List.
- List list=new ArrayList();
- //Adding elements in the List.
- list.add(“Mango”);
- list.add(“Apple”);

#### How stack is implemented?

A stack can be implemented by means of Array, Structure, Pointer, and Linked List. Stack can either be a fixed size one or it may have a sense of dynamic resizing. Here, we are going to implement stack using arrays, which makes it a fixed size stack implementation.

**How to create a stack using ArrayList in Java?**

Implementation of Stack using ArrayList in Java. 1 push – To push the elements (Objects) into the Stack. 2 pop – To pop the top Object from the Stack. 3 peek – To view the Top Object . This will not modify the Stack. 4 size – Get the size of the Stack. 5 isEmpty – to check if the Stack is empty or not.

**Can a stack be implemented using an array?**

A stack can be implemented in different ways and these implementations are hidden from the user. For example, as stated above, we can implement a stack using a linked list or an array.

## Can a linked list be used to make a stack?

However, we will restrict the linked list or the array being used to make the stack so that any element can be added at the top or can also be removed from the top only. A stack supports few basic operations and we need to implement all these operations (either with a linked list or an array) to make a stack.

## What is the internal implementation of an ArrayList?

In the case of ArrayList, the internal storage is a object [], so the implementation is not optimal for storing value types as they will be boxed and stored in the heap too. Okay, you asked what the implementation of an arrayList is, here it is : arraylist.cs