Data types
Whenever we define some data in java, compulsory we should tell what type of data it is.
By using data type we can tell what type of data it is
There are two data types
1. Primitive data types
Byte ----> 1 byte (8 bits)
Short ----> 2 bytes (16 bits)
Int --------> 4 bytes (32 bits)
Long ------> 8 bytes (64 bits)
Float-------> 4 bytes (32 bits)
Double------> 8 bytes(64 bits)
Char ---------> 2 bytes (16 bits)
Boolean-------> 1 bit
2. Non-primitive data types
String
Arrays
etc
Integer data types
----------------------------
Whole numbers
byte -------> -128 to + 127
Ex: 45
short ------> -32768 to +32767
Ex: 456
int ---------> -2147483648 to +2147483647 ( -2^31 to 2^31-1 )
Ex: 98768765
long -------> -2^63 to +263-1
Ex: 9166691345 l
In java whenever we want to convey the data as long suffix the data with l
Floating-point data types:
-----------------------------------
real numbers
To represent real numbers we have a data type called floating-point data
whenever our data have 0-6 decimal place of accuracy then go for float.
float -----------> 0-6 (f) ---------------> 4 bytes(32 bits) //suffix with f
Ex: 32.12f, 34567231.1f,56677.99f
double ---------> 6+ -------------------> 8 bytes (64 bits)
Ex: 546.98768767, 5.97865423
>>> class Data_Types{ // access specifier optional, class keyword, class name, start of a class
// data is constant, access specifier, data type, variable name, data.
// static
static public byte bnum=100;
static public short snum=1000;
static public int inum= 1000000;
static public long lnum=8890768768l;
static public float fnum=98.89f;
static public double dnum=78.9876597;
// data is constant, access specifier is optional, data type, variable name, data.
// static
static byte bnum=100;
static short snum=1000;
static int inum= 1000000;
static long lnum=8890768768l;
static float fnum=98.89f;
static double dnum=78.9876597;
// data is not constant, access specifier, data type, variable name,data
// non-static
public byte bnum=100;
public short snum=1000;
public int inum= 1000000;
public long lnum=8890768768l;
public float fnum=98.89f;
public double dnum=78.9876597;
// data is going to change means constant, access specifier is optional, data type, variable name, data
// non-static
byte bnum=100;
short snum=1000;
int inum= 1000000;
long lnum=8890768768l;
float fnum=98.89f;
double dnum=78.9876597;
} // end of a class
