Data Type

Data type reserve memory for data. They define two things

byte -> -128 TO 127 (inc) -> 1 byte
short -> -32,768 TO 32,767 (inc) -> 2 bytes
long -> 9,223,372,036,854,775,807 TO 9,223,372,036,854,775,807 (inc) [(2^63) TO (2^63)-1] -> 8 bytes
int -> 2147483647 TO 2147483647 (inc) [(2^31) TO (2^31)-1] -> 4 bytes
float -> 3.40282347x10^(38) TO 1.40239846x10^(-45) (inc) -> 4 bytes
char -> '\u0000' OR 0 TO '\uffff' OR 65,535 (inc) -> 2 bytes
Double -> 1.79769313486x10^(308) TO 4.94065645841x10^(-324) (inc) {default val for decimal values} -> 8 bytes
boolean -> true OR false -> 1 bit key: (inc: included)

In Java, there is no signed, unsigned data type because by default here signed is there
Size of data type does not change from one OS to another OS
(byte, short, int, long) belongs to integer type
(Double) belongs to float type
In float, 7 decimal digits after decimal point are displayed
In Double, 15 decimal digits after decimal point are displayed
(char) belongs to character type
- In Java, size of char is 2 byte; because of this, it supports large range of characters
- In Java, we can use 18 international languages because of large range of characters
(boolean) belongs to boolean type
- It is used for storing logical values, i.e. either true or false.
- Java Boolean datatype takes 0 byte of main memory space because it is implemented with general purpose register which allows to store 1 bit of information where (1 for true) and (0 for false)