Data Types used in Java

G C Reddy

2 years ago

Data Types used in Java, What is Data Type?, Primitive Data Types, Non-primitive Data Types, and Data type conversion in Java programming.

Selenium Online Training with Project (by G C Reddy)

Data Types are used in computer programming to store and organise different types of data.

Data Types used in Java

1. Data Type is a classification of the type of data that a variable or final variable/constant or method can store in a computer program

Data types are used in four area in Java Programs.

a. Declaring Variables
b. Declaring Final Variables/Constant
c. Declaring Methods (methods with return a value)
d. Method Arguments

Example:

1.
int x=100;
String country=”India”;

2.
public int add(int num1, int num2) {
int result;
result=num1+num2;
return result;
}

3.
(int num1, int num2)

4.
final int price=1000;

2. Data Types specify sizes and types that can be stored in a variable.

byte a=100;
short b=10000;
int c=100000;
long d=9898787876l;

String x=”Hyderabad”;
char y=’R’;
boolean z= true;

3. Java Supports Explicit Declaration of data types

Java:

int x;
x=100;
x=10.23; //Invalid
y=200;

Python:

x=100
.
.
x=”India”
.
.
x=10.234

4. Java Data Type Conversion

Assign Values to Variables is two types
1. Initialisation
int x=100;
int y;
.
.
y=1234;

2. Reading
Read User Input
Read data from files

Whenever we read data in a computer program then the program considers the data as String type data, we need convert the data to perform mathematical operations.

India – > “India” – No conversion
100 -> “100” – Convert the String type data to integer type
10.234 – > “10.234” – Convert the String type data to float type

Ex:
String num1=”10″;
String num2=”20″;

System.out.println(num1+num2);//1020
int x= Integer.parseInt(num1);
int y= Integer.parseInt(num2);
System.out.println(x+y);//20

5. Important Java Types

a. Primitive Data Types

i. byte
Ex: byte a=100;

ii. short
Ex: short b=1000;

iii. int
Ex: int c=10000000;

iv. long
Ex: long d=998787879l;

v. float
Ex: float e=123.456f;

vi. duble
duble f= 8787878.98345;

vii. char
Ex: char g=’Y’;

viii. booean
booean h=false;