Data Types:
● Java is safe and
robustness because of data Types.
● in
C/C++ you can assign a floating-point value to an integer. In Java we
cannot assign a floating-point value
to an integer.
● Java defines eight types
of data: byte, short, int, long, char, float,
double, and Boolean. These can be put in four groups as follows.
Integers:-
● This group includes byte, short, int, and long,
which are for whole valued signed numbers.
byte: The smallest integer type
is byte. This is a signed 8-bit type that has a range from –128 to 127.
Variables of type byte are especially useful when you’re working with a
stream of data from a network or file.
Byte
variables are declared by use of the byte keyword.
For example:
byte a = 50, b = -50;
a and b default
value is 0.
short: short is a
signed 16-bit type. It has a range from –32,768 to 32,767.This . A short is 2 times smaller than an int.
Short variables are
declared by use of the short keyword.
For example, declares two
short variables called a and b:
short a = 105000 ,b = -150000;
a and b default
value is 0
Int: The most commonly used
integer type is int. It is a signed 32-bit type that has a range from
–2,147,483,648 to 2,147,483,647. Int are commonly used to control loops
and to index arrays.
Int variables are
declared by use of the int keyword.
For example, declares two
int variables called a and b:
int a = 10500 ,b = -150000;
a and b default
value is 0
long: long is a
signed 64-bit It has a range from –9,223,372,036,854,775,808 to
9,223,372,036,854,775,807. This type it useful when big numbers
are needed.
Long
variables are declared by use of the long keyword.
For example, declares two long variables called a and b:
long a = 100000L ,b= 100000L;
a and b default
value is 0
Floating-point
numbers :-
● This group
includes float and double, which represent numbers with
fractional precision. Floating-point numbers, also known as real numbers,
are used when evaluating expressions that require fractional precision.
float: The type float specifies
a single-precision value
that uses 32 bits of storage. Variables of type float
are useful when you need a fractional component, but don’t require a large
degree of precision.
For example, declares two float variables called a and b:
float b =
245.5f, c = 14.5f;
a and b
default value is 0.0f.
double: Double precision, as
denoted by the double keyword, uses 64 bits to store a value.
All transcendental math
functions, such as sin( ), cos( ), and sqrt( ), return double
values.
For example, declares two
double variables called a and b:
double a = 1234.5
, b = 234.5;
a and b
default value is 0.0d.
Characters:-
● This group includes char,
which represents symbols in a character set, like letters and
numbers.
char: char data
type is a single 16-bit Unicode character. The range of a char is
0 to 65,536. The standard set of characters known as ASCII still ranges from 0
to 127. char minimum value is '\u0000' or 0 and maximum value is '\uffff'
or 65,535.
Example: char a
= ‘A’;
Booleans:-
● This group includes boolean, which is a special
type for representing true/false values.
boolean: is
logical values. It represent one bit of information.
Example:
boolean a = true;
Default
value of a is false.
