#ENQUEUE DEQUEUE JAVA DOCUMENTATION FULL#

#ENQUEUE DEQUEUE JAVA DOCUMENTATION FULL#

If it is full it throws an Exception else it simply adds an element to the stack and increment the topIndex by 1. The push() method first checks if the stack is full. The empty() method checks if the topIndex is at -1 which implies, the stack is empty. The size() method returns the size of the stack i.e. We initialize the data array and topIndex in the constructor method. Default Array capacity is 1000 for the stack where capacity is not mentioned. There are two constructor methods, one with capacity customed by the user and the other default. We declare an array named data to store the values and topIndex to keep track of the top element. We can make a stack of String datatype, of Integer datatype, or Character datatype. It enables the user to use any data type. We name our class as ArrayStack as we are using Array to store our data.Į in Angular brackets () makes our class Generic. It will have the same functionality as we saw in the above examples. We are implementing our own stack using class and methods. Implementation of Stack Using Array in Java This package contains stack Data Structure, which will allow us to create a stack, insert data into it and use all the other functionalities of the stack. The Stack class extends the Vector class.įirstly we need to import package. The Java collections framework has a Stack Class that provides the functionality of the Stack Data structure. Also we can check if the stack is empty using the empty() method. We can see the topmost element in the stack using peek() we can know the size of the stack using the size() method. We can perform various operations on stack other than push() and pop(). These operations are also performed using stacks. You must have also observed the Back and Forward buttons on browsers. When you make changes, it pushes changes onto the stack. When you undo something, it pops the most recent action.

One such application is the undo mechanism in text editors. No element can be retrieved, removed, or added from the middle of the stack. Likely, elements can be added to the stack at the top, and they can be seen or removed from the top. We cannot add or remove a plate at the middle of the stack. So, when we need a plate, we take (pop) from the top of the stack, and when we want to add a plate, we put (push) it at the top as well. The name “stack” is derived from a stack of plates. Introduction to Stack in JavaĪ stack is a collection of objects that are inserted and removed in a LIFO(Last In First Out) fashion. Stack and Queue both are Linear Data Structures. They are used to store the same type of data and retrieve the data in a specific order. Stack and Queue are fundamental data structures in Java Collections Framework.

Enqueue dequeue java documentation