Data Types in java

Data Types in java

There are three main data types for java

1.Integer

2.String

3.Floating point

Integer

It used to store number 

ie.   int a; "declaration of variable a"

int a=2; "initialize value 2 for variable a;

There are four types of integer

TYPE     SIZE

 byte      one byte

short     two byte

int          four byte

long       eight byte

•       To make the integer long L or 1 is require at the end of number

         623L or 6231

Example

class integers

{

public static void main(String[] args)

{

byte b=22;

short s=1234;

int a=1324356;

long j=12345676543L ;

System.out.println("b= "+b);

System.out.println("s= "+s);

System.out.println("a= "+a);

System.out.println("j= "+b);

}

}

In above example we take all the types of integers

and print their value

String

It used to store sequence of character

creation of String

ie. String name=""; //Empty string

     String name="Alex" //character series.

Substring

We can take small String (Substring) from larger String

in this method

String  Welcome="Helloworld"

String  z=greeting substring (0,3) //we take the character from 0 up to <3;

Means we copy 0,1,2 from position 0 to position 2

Here we get substring s with characters “Hel”

Calculate the length of substring

Suppose we have the substring

String  z=greeting substring (Y,Z);

Then string length=Z-Y

String  z=greeting substring (0,3)

Length for above substring=3-0=3

Concatenation of strings

Concatenation is use for joining of two string with

+ sing

Example

class concatenation

{

public static void main(String[] args)

{

  String one="Hello";

 String two="World";

String three=one + two; //joining of two string

System.out.println(three);

}

}                 

In above program we get output “HelloWorld”

+ sing join two string in order they are arrive

 Floating point

It store the number containing fractional parts

Ie. Float  a=33.40,b=22.12;

Floating point type

TYPE    SIZE

 float       4 byte(approximately 7 decimal digit)

double    8 byte(approximately 15 decimal digit)

Floating point number have suffix F(for example 2.33F)

And the floating point number without an F suffix (such as 2.33)

Is conceder as of type double

Double is the type of floating point.

For mathematical function such as sin, cos double is require

Example:

class type

{

public static void main (String[] args )

{

float a=3.14F;

double b=0.0000000332;

System.out.println("a="+a);

System.out.println("b="+b);

}

}

In above program we print the value of a and b