Introduction to Data Type (JAVA)

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CHAPTER 1 :INTRODUCTION

1.1 Motivation for studying data structure

1.2.1 Primitive Type

1.2.2 Abstract Data Type

1.3 Data Structure Concept

1.3.1 Static Data Structure

1.3.2 Dynamic Data Structure1.3.3 Operations on data structure

1.4 Application of structure data1


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A ood a lication can solve roblems o timall

minimize running time and efficiently use memory space.

structure.

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1.2 In r i n D T

In Java ro rammin all variables are re uired to have

aData Type.

a) Fundamental /Primitive /Base Type

b) Abstract Data Type

a) Fundamental Type

Ei ht Java fundamental data t es are int, float,

double, long, short, char, boolean and byte

A variable of the fundamental type simply store a

.

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1.2 Introduction to Data Type (cont)

a) 8 fundamental types

int: 32-bit signed twos complement

integerfloat: 32-bit floating-point number

ou e: - t oat ng-po nt num er

long: 64-bit signed twos complement

short:16-bit signed twos complement

inte er

char: 16-bit unicode character

boolean: boolean value true or false

byte: 8-bit signed twos complement integer

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ADT is also referred to as anobject.

ADT containsmore than one fundamental data types.

ADT also containsthe methods as an inter ace to mani ulate the

data.Each ADT is an encapsulation of data and methods.

In Java, ADT or object is defined using Class. Eg:

class Computer {

private int code;private String brand;

private double price;

pu c ompu erpublic Computer (int c, String b, double p) {}

public int getCode () { return code; }

public double getPr() { return price; };

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ADT can be used by any application program,

it eliminates rewriting the code if there arechanges in the implementation of the data /

o ect.

-

interfaces by having the set of methods in the

classes.

ADThides the implementation of the methods

in the encapsulation feature of the object.

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Abstract Data Type

Using class to create ADT

Classes are used to represent objects in Object

Oriented Programming (OOP) approach.

Class contains :

Member data - a set of field (data) -

OOP uses classes to encapsulate data (attributes) and

methods (behaviors).

Enca sulate enables ob ects to hide their

implementation from other objects.

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Abstract Data Type (cont)

Objects can communicate with one and

another across well defined interfaces (

methods).

implemented.

Pro rammer usesclasses to instantiate ob ects

that work together to implement the system

(using OOP approach)

Programmer can create their own ADTdepends on their needs (using OOP approach)

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1.3 Data Structure Concept

Data Structure is a concept on how to

structure represent an man pu ate ata

(store, process, access and etc) in the

program.

Data structure is known asa collection of re a e a a ems.

Two types of Data Structure :

a c a a ruc ure xe -s zeDynamic Data Structure

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Data Structure Conce t cont.1.3.1 Static Data Structure

Data is re resented with a s ecific/fixed memor

allocation.Example :

1.3.2 Dynamic Data StructureData can bea ocated anywhere in the memory and

reference is used to point to the data

D namic Data Structure can row and shrink at

execution time.Uses reference or dynamic memory allocation

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Data Structure Concept (cont.)

Example : Static/Fixed-Size Data Structure

Arrays :

contagiously in memory (adjacent to each other).Arrays arefixed-length entities with the capacity that is

specified during the creation / declaration time and the

length remains until end of program.

Arra s in JAVA are ob ects and its considered asre erence

type.

The elements of a JAVA array can be eitherprimitive types or

.Example : primitive types

int c[ ]; // declare an int array

c = new int[10]; // create an array of int with 10 elements

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Data Structure Concept (cont.)

Example : ADT

public class Student{

private String name;

private double gpa;

..

}

public static void main(String[] arg)

{ ..

Student Stu[ ]; // declares the array of objectStu = new Student[12];// creates the array of student (object)

}

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Data Structure Conce t cont.1.3.3 Operations on Data Structure

Some basic operations are:

. Adding

- Insert data into the structure.ii. Deleting

- .

iii. Updating

- Modify data in the structure

- Find a particular data in the structure base on a criterion

(keyword). It can be the location or the element to be searched.

v. Sortin

- Sort or organize data in the structure base on a criterion(keyword). It can be in ascending or descending order.

vi. Traversal

- Access each data in the structure and process them at least once.

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1.4 Data Structure Application

There are many data structure applications, some of the

major ones are:

st

List is an ordered sequence elements.contains a number of elements that is less than or

equal to its capacity.

Two types of list :

data in a contiguous memory (elements next to

each other)

Linked list a linked structure that store data

where one element refers to another, anywhere

in memory

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Data Structure Application (cont.)

Stacks

insertion and deletions are made from thetop of a stack

Queuerepresent a wa t ng nes an use n any

queue eg. printing queue and request queue

deletions are made from the front of a

ueue.

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Data Structure A lication cont.

Facilitate high speed searching andsorting of data.

Store high volume of data with the links

from one element to another anywheren memory

Eliminate duplicate data efficiently

expressions into machine language.

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Introduction to Data Type (JAVA)

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