EDUCBA

EDUCBA

MENUMENU
  • Free Tutorials
  • Free Courses
  • Certification Courses
  • 600+ Courses All in One Bundle
  • Login

Data Types in Java

Home » Software Development » Software Development Tutorials » Java Tutorial » Data Types in Java

Data Types in Java

Introduction to Data Types in Java

Data type is a keyword, it describes the type of data. Data types are having different sizes and values and the values are stored in a variable. Java data types are broadly categorized into Primitive data types and Non primitive data types. Primitive data types are char, byte, short, int, long, float, double, boolean. Non primitive data type is String.

How Data Types come into Picture?

Java allows 3 types of constants.

Start Your Free Software Development Course

Web development, programming languages, Software testing & others

Java allows 3 types

  • Character constant
  • Numeric constant
  • Boolean constant

1. Character constant

Character constants are alphabets, words, special symbols and digits (0-9).

In Java 2 types of character constants are there.

  • Single character constant
  • String constant

a. Single character constant: Single character constant is defined as”single letter surrounded in single quotes (‘ ’)”. Data type is char.

Example: ‘4’, ‘a’,’ ’(empty space) etc.

Limitation: We should not declare more than one character in single quotes, if do so java compiler complains about it.

Example: ‘12’ is wrong declaration.

b. String constant: String constants are “group of letters enclosed in double quotes”. Data type is string.

Example: ”Amardeep”, “!@#$”, “1234”,”30-Mar-1995” etc

2. Numeric constant

All numbers in java are said to numeric constants only.

Popular Course in this category
Java Training (40 Courses, 29 Projects, 4 Quizzes)40 Online Courses | 29 Hands-on Projects | 285+ Hours | Verifiable Certificate of Completion | Lifetime Access | 4 Quizzes with Solutions
4.8 (8,411 ratings)
Course Price

View Course

Related Courses
JavaScript Training Program (39 Courses, 23 Projects, 4 Quizzes)jQuery Training (8 Courses, 5 Projects)Free Java Online CourseJavaFX Training (1 Courses)

There are 2 types of numeric constants.

  • Integer numeric constant
  • Decimal/real/floating point numeric constant

a. Integer numeric constant: A number without fractional part is called as Integer numeric constant. Data type is int.

Example: -1, -2, -5, 6, 7, 8, 0 etc.

b. Decimal/real/floating point numeric constant: A number with fractional part is called as decimal or floating numeric constant. Data types are float and double.

Example: -1.23, 1.23, 5.67, 7.0, 5.28 etc.

3. Boolean constant

Java stores Boolean values as true or Data type is boolean.

Example: true, false

Data Summary

Given below is the data summary:

  • Single character constant
  • String constant
  • Integer constant
  • Decimal constant
  • Boolean constant

Java Data Types

Java data types are categorized into 2 types:

1. Unsigned

There is no sign bit allocation for memory means we don’t have any positive or negative value for characters.

Examples: a. Characters

2. Signed

There is sign bit allocation for memory means integers and decimal numbers have positive and negative values. So every first bit allotted for -(minus) or + (plus) sign bit and rest of the bits are allotted for number. For negative number sign bit is 1 and positive number sign bit is 0.

Sign Bit-1 2 3 4 5 …… …… …… …… ……

Examples:

  • Integer
  • Decimal
  • String

1. Integer classification

Integer again is classified into 4 data types.

  • byte: byte has 1 byte memory. 1 byte has 8 bits. As we have seen 1st bit is for sign bit and rest 7 bits are for number. Therefore byte size in java 2^-7 to (2^7)-1 means -128 to 127.
  • short: short has 2 bytes memory. 2 bytes have 16 bits. As we have seen 1st bit is for sign bit and rest 15 bits are for number. Therefore short size in java 2^-15 to (2^15)-1.
  • int: int has 4 bytes memory. 4 bytes have 32 bits. As we have seen 1st bit is for sign bit and rest 31 bits are for number. Therefore int size in java 2^-31 to (2^31)-1.
  • long: long has 8 bytes memory. 8 bytes have 64 bits. As we have seen 1st bit is for sign bit and rest 63 bits are for number. Therefore long size in java 2^-63 to (2^63)-1.

2. Decimal classification

Decimal again is classified into 2 data types.

  • float: float has 4 bytes memory. 4 bytes have 32 bits. As we have seen 1st bit is for sign bit and rest 31 bits are for number. float size in java 3.4E^-38 to 3.4E^38.
  • double: double has 8 bytes memory. 8 bytes have 64 bits. As we have seen 1st bit is for sign bit and rest 63 bits are for number. double size in java 1.7E^-308 to 1.7E^308.

3. String

String is also unsigned data type in java.

Data types table:

S.No Data Data Type Signed/Unsigned Size Ranges
1 Single character constant char Unsigned 2 bytes 0 to 65535
2 Integer constant byte Signed 1 byte 2^-7 to (2^7)-1
short Signed 2 bytes 2^-15 to (2^15)-1
int Signed 4 bytes 2^-31 to (2^31)-1
long Signed 8 bytes 2^-63 to (2^63)-1
3 Decimal constant float Signed 4 bytes 3.4E^-38 to 3.4E^38
double Signed 8 bytes 1.7E^-308 to 1.7E^308
4 Boolean constant boolean Signed JVM dependent true/false
5 String constant String Signed JVM dependent JVM dependent

Classification of Java Data Types

Given below is the classification of Java Data Types:

  • Primitive data type
  • Reference data type

1. Primitive data type

Among 9 data types 8 are primitive data types.

  • char
  • byte
  • short
  • int
  • long
  • float
  • double
  • Boolean

2. Reference data type

Among 9 data type’s only one reference type is there.

  • String: It is also called class type.

Why Java char has 2 Bytes and other Programming Languages have 1 Byte Memory?

  • Java has designed by using UTF-16 ( Unicode Transformed Format).
  • Originally the char data type used for representing 16 bit Unicode.
  • So Java char has 2 bytes.

How does Data Types work in Java?

Based on type assigned to a variable then corresponding operation performs.

Syntax: Primitive data types

1. char

char variableName=value;

2. byte

byte variableName=value;

3. short

short variableName=value;

4. int

int varibaleName=value;

5. long

long varibaleName=value;

6. float

float varibaleName=value;

7. double

double varibaleName=value;

8. boolean

booleanvaribaleName=value;

Syntax: Reference data type

1. String

String variableName=value;

Default values for data types are given below:

Data Types in Java 1

Examples of Data Types in Java

Given below are the examples mentioned:

Example #1: Character values

Code:

public class Characters
{
//char global declaration
static char global;
public static void main(String[] args) {
//char local decalration
char a='a';
char b='b';
char c='c';
char d='d';
System.out.println("Character with char data type");
System.out.println(global);//gives you default value with empty means '\u0000'
System.out.println(a);
System.out.println(b);
System.out.println(c);
System.out.println(d);
}
}

Output:

Data Types in Java 2

Example #2: String

Code:

public class StringDemo {
static String globalString;
public static void main(String[] args) {
String name1="Amardeep";
String specialChars="@#$%^";
System.out.println("Strings with String data type");
System.out.println(globalString);
System.out.println(name1);
System.out.println(specialChars);
}
}

Output:

Data Types in Java 3

Example #3: Integer data type

Code:

public class IntegerDataTypes {
static byte globalByte;
static short globalShort;
static int globalInt;
static long globalLong;
public static void main(String[] args) {
byte b=-128;
short s=23456;
int i=432198;
long l=34534534L;//we can specify long value by suffix L
System.out.println("Default Integer values byte :"+globalByte+" short :"+globalShort+" int :"+globalInt+" long :"+globalLong);
System.out.println("Integer values byte :"+b+" short :"+s+" int :"+i+" long :"+l);
}
}

Output:

Integer

Example #4: Decimal data type

Code:

public class DecimalDataType {
static float globalFloat;
static double globalDouble;
public static void main(String[] args) {
float f=2538.23f;//we can specify float value by suffix f
double d=2358.36d;//we can specify double value by suffix d
System.out.println("Default Decimal value float :"+globalFloat+" double :"+globalDouble);
System.out.println("Decimal values float :"+f+" double :"+d);
}
}

Output:

Decimal

Example #5: Boolean data type

Code:

public class BooleanDataType {
static booleanglobalBoolean;
public static void main(String[] args) {
boolean b=true;
System.out.println("Default booleanvalue :"+globalBoolean);
System.out.println("Boolean value:"+b);
}
}

Output:

Boolean

Conclusion

Data Types in Java are primitive and reference types char, byte, short, int, long, float, double, boolean and String respectively. Data types decides the behavior of data.

Recommended Articles

This is a guide to Data Types in Java. Here we discuss the introduction to Data Types in Java, classification of data types, how does these work, and examples. You may also have a look at the following articles to learn more –

  1. Java.net URI
  2. Java NullPointerException
  3. java.net Package
  4. Java hashCode()

All in One Software Development Bundle (600+ Courses, 50+ projects)

600+ Online Courses

50+ projects

3000+ Hours

Verifiable Certificates

Lifetime Access

Learn More

0 Shares
Share
Tweet
Share
Primary Sidebar
Java Tutorial
  • Basic
    • What is Java?
    • What is JNDI in Java
    • What is JNI in Java
    • What is Java Interface
    • What is Java SE
    • What is JavaBeans
    • Install JDK
    • Java Programming Language Features
    • Applications of Java
    • Career in Java
    • Versions of Java
    • Careers as Java Developer
    • Java Virtual Machine
    • Java GUI Framework
    • Java Packages
    • Java Package Example
    • Default Package in Java
    • Variables in Java
    • Instance Variable in Java
    • Object in Java
    • Java Commands
    • Iterator in Java
    • Java Booleans
    • Conversion in Java
    • Type Conversion in Java
    • String in Java
    • What is JDK
    • What is JVM
    • What is J2EE
    • RMI Architecture
    • Java Literals
    • Data Types in Java
    • Primitive Data Types in Java
    • Enumset in Java
    • Cheat Sheet Java
    • IntelliJ Cheat Sheet
  • Frameworks
    • Best Java Compilers
    • Frameworks In Java
    • Testing Frameworks for Java
    • Java Monitoring Tool
    • Best Java IDE
    • Java Compilers
    • Java Tools
    • Java Deployment Tools
    • Types of Memory in Java
    • Java References
    • Java Type Inference
    • Java Boolean to String
    • Java String to Float
    • java.net Package
    • Java Formatter
  • Operators
    • Arithmetic Operators in Java
    • Unary Operators in Java
    • Logical Operators in Java
    • Comparison Operators in Java
    • Assignment Operators in Java
    • Java String Operators
    • Conditional Operator in Java
    • Boolean operators in Java
  • Keywords
    • Java Keywords
    • this Keyword in Java
    • Static Keyword in Java
    • Native keyword in Java
    • Throw Keyword in Java
    • Throws Keyword in Java
    • What is public in Java?
    • Private in Java
    • Protected Keyword in Java
    • Final Keyword in Java
  • Control statements
    • Control Statement in Java
    • Else-If Statement in Java
    • Nested if Statements in Java
    • Continue Statement in Java
    • Break Statement in Java
    • Case Statement in Java
  • Loops
    • Loops in Java Programming
    • For Loop in Java
    • While Loop in Java
    • do-while loop in Java
    • For-Each loop in Java
    • Nested Loop in Java
  • Inheritance
    • Inheritance in Java
    • Single Inheritance in Java
    • Multilevel Inheritance in Java
    • Hierarchical Inheritance in Java
    • Hybrid Inheritance in Java
  • Constructor and destructor
    • Constructor and Destructor in Java
    • Constructor in Java
    • Destructor in Java
    • Copy Constructor In Java
    • Static Constructor in Java
    • Private Constructor in Java
  • Array
    • Arrays in Java Programming
    • 2D Arrays in Java
    • 3D Arrays in Java
    • Multidimensional Array in Java
    • Array Methods in Java
    • Print 2D Array in Java
    • Print Array in Java
    • String Array in Java
    • Associative Array in Java
    • Dynamic Array in Java
    • Java Array Iterator
    • Java array.push
  • Sorting
    • Sorting in Java
    • Sorting Algorithms in Java
    • Merge Sorting Algorithms in Java
    • Quick Sorting Algorithms in Java
    • Selection Sort In Java
    • Heap Sort In Java
    • Bubble Sort in Java
    • Merge Sort In Java
    • Quick Sort in Java
    • Insertion Sort in Java
    • Program for Merge Sort in Java
  • Functions
    • String Functions in java
    • Math Functions in Java
    • Hashing Function in Java
    • Regular Expressions in Java
    • Recursion in Java
    • Java Callback Function
    • Java Call by Value
    • Java Call by Reference
    • HashMap in Java
    • Java String Concatenation
    • Java String Equals
    • Virtual Function in Java
    • Java newInstance()
    • split() Function in Java
    • trim() Function in Java
    • Replace() Function in Java
    • substring() Function in Java
    • Strictfp in Java
    • String Reverse Function in Java
    • Java String getBytes
    • Java Replace Char in String
    • Shuffle() in Java
    • addAll() in Java
    • FileWriter in Java
    • Java Stream Filter
    • Java FileInputStream
    • replaceAll() in Java
    • repaint in Java
    • copy() in Java
    • Java max()
    • Java min()
    • Java Timestamp
    • Java URLConnection
    • Java StringJoiner
    • Java KeyStore
    • Java InetAddress
    • Java getMethod()
    • swap() in Java
    • Deadlock in Java
    • Range in Java
    • Java Repository
    • Java Dictionary
    • Calculator in Java
    • Mutable String in Java
    • Mutable vs Immutable Java
    • Native Methods in Java
    • StringBuffer Class in Java
    • String Class in Java
    • Java URL Class
    • Java Vector Class
  • Polymorphism
    • What is Polymorphism
    • Polymorphism in Java
    • Runtime Polymorphism in Java
    • Overloading and Overriding in Java
    • Overloading in Java
    • Method Overloading in Java
    • Function Overloading in Java
    • Overriding in Java
    • Method Overriding in Java
    • Final Keyword in Java
    • Super Keyword in Java
    • instanceOf in Java
    • Java Authenticator
    • Java Alias
  • Collections
    • What is TreeMap in Java?
    • Sorting in Collection
    • Java Collections Class
    • Hashtable in Java
    • Java EnumMap
    • Java LinkedHashMap
    • Reverse Linked List in Java
    • LinkedList in Java
  • Date Time
    • java.util.Date
    • Java Clock
    • Java Instant
    • Java LocalTime
    • Java ZoneId
    • Java ZoneOffset
    • Java varargs
    • Java LocalDate
    • Java OffsetDateTime
    • Java LocalDateTime
    • Java Duration
    • Java DayOfWeek
    • Java Period
    • Timer in Java
    • Java TimeZone
  • Advanced
    • Methods in Java
    • Inner Class in Java
    • Anonymous Inner Class in Java
    • Java Stack Methods
    • Java Static Nested Class
    • Synchronized Block in Java
    • Static Synchronization in Java
    • Abstract Class in Java
    • Access Modifiers in Java
    • Non Access Modifiers in Java
    • Bit Manipulation in Java
    • Encapsulation in Java
    • Singleton Class in Java
    • Wrapper Class in Java
    • Nested Class in Java
    • Java Matcher
    • Java Pattern Class
    • Java File Class
    • Final Class in Java
    • Stack Class in Java
    • Anonymous Class in Java
    • StringBuilder Class in Java
    • StringBuffer in Java
    • Java Directories
    • JSON in Java
    • Object Class in Java
    • What is Multithreading in java
    • Java Thread Priority
    • Daemon Thread in Java
    • Java Thread Pool
    • Java ThreadLocal
    • Association in Java
    • Queue in Java
    • Functional Programming in Java
    • ClassLoader in Java
    • Interface in Java
    • Functional Interface in Java
    • Java Queue Interface
    • Collection Interface in Java
    • Object Cloning in Java
    • Java.net URI
    • Java Assertion
    • Vector in Java
    • Applets in Java
    • Template in Java
    • Java Shutdown Hook
    • 2D Graphics in Java
    • Autoboxing and Unboxing in Java
    • Comparable in Java Example
    • Java Annotations
    • Java User Input
    • Serialization in Java
    • Dynamic Binding in Java
    • Java Parse String
    • Java Adapter Classes
    • Immutable Class in Java
    • String Initialization in Java
    • String Manipulation in Java
    • ThreadGroup in Java
    • Java Iterate Map
    • Java IO
    • Java?OutputStreamWriter
    • DataInputStream in Java
    • Java BufferedReader
    • Java BufferedWriter
    • Java BufferedInputStream
    • Java ByteArrayInputStream
    • Java ByteArrayOutputStream
    • Java RandomAcessFile
    • Java PrintStream
    • Java PrintWriter
    • Java URLEncoder
    • Java Scanner Class
    • Java Console
    • Java Runtime class
    • Java Base64
    • Java Base64 Encoding
    • Java Base64?Decode
    • Finalize in Java
    • Java Parallel Stream
    • Java Getter Setter
    • Set Interface in Java
    • How to Connect Database in Java
    • How to Create Webservice in Java
    • Composition in Java
    • BinarySearch() in Java
    • Exception Handling in Java
    • Java NullPointerException
    • Java NoSuchElementException
    • Java ConcurrentModificationException
    • Java ArithmeticException
    • Java IOException
    • Java RuntimeException
    • NumberFormatException in Java
    • Java ArrayIndexOutOfBoundsException
    • Java ClassNotFoundException
    • Java FileNotFoundException
    • Java InterruptedException
    • Finally in Java
    • Java Default Method
    • Java Locale
    • Tuples in Java
    • Java ServerSocket
    • Java Lambda Expressions
    • Java DatagramSocket
    • Java Animation
  • MISc
    • What is Synchronization in Java
    • What is Concurrency in Java
    • What is Design Pattern in Java
    • What is Generics in Java
    • What is API in Java
    • What is a Binary Tree in Java
    • What is Java Garbage Collector
    • What is Java Inheritance
    • Thread Life cycle in Java
    • Object Oriented Programming in Java
    • Java App Development
    • Java Naming Conventions
    • Java hashCode()
    • Java Transient
    • JSTL In Java
    • Comparable in Java 
    • Aggregation in Java
    • EJB in Java
    • @deprecated in Java
    • Java @Inherited
    • @SuppressWarnings in Java
    • Java @Override
  • Programs
    • Patterns in Java
    • Star Patterns in Java
    • Number Patterns in Java
    • Swapping in Java
    • Factorial in Java
    • Fibonacci Series in Java
    • Reverse Number in Java
    • Palindrome in Java
    • Armstrong Number in Java
    • Squares in Java
    • Square Root in Java
    • Special Number in Java
    • Anagram Program in Java
    • Strong Number in Java
    • Random Number Generator in Java
    • Matrix Multiplication in Java
    • Socket Programming in Java
    • Prime Numbers in Java
    • String Comparison in Java
    • Leap Year Program in Java
    • Reverse String in Java
    • Design Patterns in Java
    • Happy Numbers in Java
  • Interview Questions
    • Java Interview Questions
    • Java Inheritance Interview Questions
    • Java EE Interview Questions
    • Java Developer Interview Questions
    • Java Collection Interview Questions
    • Java Interview Question on Multithreading
    • Java String interview question
    • Java Testing Interview Questions
    • Java Multi-threading Interview Questions
    • Multithreading Interview Questions in Java
    • Oops Java Interview Questions
    • Java Spring Interview Questions
    • Data Structure Java Interview Questions
    • Java Web Services Interview Questions

Related Courses

Java Course

JavaScript Certification Course

jQuery Training Course

Java Training Courses

Free Java Training Courses

JavaFX Training

Java Training Course

Footer
About Us
  • Blog
  • Who is EDUCBA?
  • Sign Up
  • Corporate Training
  • Certificate from Top Institutions
  • Contact Us
  • Verifiable Certificate
  • Reviews
  • Terms and Conditions
  • Privacy Policy
  •  
Apps
  • iPhone & iPad
  • Android
Resources
  • Free Courses
  • Java Tutorials
  • Python Tutorials
  • All Tutorials
Certification Courses
  • All Courses
  • Software Development Course - All in One Bundle
  • Become a Python Developer
  • Java Course
  • Become a Selenium Automation Tester
  • Become an IoT Developer
  • ASP.NET Course
  • VB.NET Course
  • PHP Course

© 2020 - EDUCBA. ALL RIGHTS RESERVED. THE CERTIFICATION NAMES ARE THE TRADEMARKS OF THEIR RESPECTIVE OWNERS.

EDUCBA
Free Software Development Course

Web development, programming languages, Software testing & others

*Please provide your correct email id. Login details for this Free course will be emailed to you
Book Your One Instructor : One Learner Free Class

Let’s Get Started

This website or its third-party tools use cookies, which are necessary to its functioning and required to achieve the purposes illustrated in the cookie policy. By closing this banner, scrolling this page, clicking a link or continuing to browse otherwise, you agree to our Privacy Policy

EDUCBA

*Please provide your correct email id. Login details for this Free course will be emailed to you
EDUCBA Login

Forgot Password?

EDUCBA
Free Software Development Course

Web development, programming languages, Software testing & others

*Please provide your correct email id. Login details for this Free course will be emailed to you

Special Offer - Java Course Learn More