Primitive Data Types
There
are eight primitive data types supported by Java. Primitive data types are
predefined by the language and named by a key word. Let us now look into detail
about the eight primitive data types.
byte:
·
Byte data type is a
8-bit signed two.s complement integer.
·
Minimum value is -128
(-2^7)
·
Maximum value is 127
(inclusive)(2^7 -1)
·
Default value is 0
·
Byte data type is used
to save space in large arrays, mainly in place of integers, since a byte is
four times smaller than an int.
·
Example : byte a = 100
, byte b = -50
short:
·
Short data type is a
16-bit signed two's complement integer.
·
Minimum value is
-32,768 (-2^15)
·
Maximum value is
32,767(inclusive) (2^15 -1)
·
Short data type can
also be used to save memory as byte data type. A short is 2 times smaller than
an int
·
Default value is 0.
·
Example : short s=
10000 , short r = -20000
int:
·
Int data type is a
32-bit signed two's complement integer.
·
Minimum value is - 2,147,483,648.(-2^31)
·
Maximum value is
2,147,483,647(inclusive).(2^31 -1)
·
Int is generally used
as the default data type for integral values unless there is a concern about
memory.
·
The default value is
0.
·
Example : int a =
100000, int b = -200000
long:
·
Long data type is a
64-bit signed two's complement integer.
·
Minimum value is
-9,223,372,036,854,775,808.(-2^63)
·
Maximum value is
9,223,372,036,854,775,807 (inclusive). (2^63 -1)
·
This type is used when
a wider range than int is needed.
·
Default value is 0L.
·
Example : int a =
100000L, int b = -200000L
float:
·
Float data type is a
single-precision 32-bit IEEE 754 floating point.
·
Float is mainly used
to save memory in large arrays of floating point numbers.
·
Default value is 0.0f.
·
Float data type is
never used for precise values such as currency.
·
Example : float f1 =
234.5f
double:
·
double data type is a
double-precision 64-bit IEEE 754 floating point.
·
This data type is
generally used as the default data type for decimal values. generally the
default choice.
·
Double data type
should never be used for precise values such as currency.
·
Default value is 0.0d.
·
Example : double d1 =
123.4
boolean:
·
boolean data type
represents one bit of information.
·
There are only two
possible values : true and false.
·
This data type is used
for simple flags that track true/false conditions.
·
Default value is
false.
·
Example : boolean one
= true
char:
·
char data type is a
single 16-bit Unicode character.
·
Minimum value is
'\u0000' (or 0).
·
Maximum value is
'\uffff' (or 65,535 inclusive).
·
Char data type is used
to store any character.
·
Example . char letterA
='A'
Java Basic Operators
Java
provides a rich set of operators to manipulate variables. We can divide all the
Java operators into the following groups:
·
Arithmetic Operators
·
Relational Operators
·
Bitwise Operators
·
Logical Operators
·
Assignment Operators
·
Misc Operators
1. The Arithmetic
Operators:
Arithmetic
operators are used in mathematical expressions in the same way that they are
used in algebra. The following table lists the arithmetic operators:
Assume
integer variable A holds 10 and variable B holds 20 then:
|
Operator
|
Description
|
Example
|
|
+
|
Addition - Adds values on either side
of the operator
|
A + B will give 30
|
|
-
|
Subtraction - Subtracts right hand
operand from left hand operand
|
A - B will give -10
|
|
*
|
Multiplication - Multiplies values on
either side of the operator
|
A * B will give 200
|
|
/
|
Division - Divides left hand operand
by right hand operand
|
B / A will give 2
|
|
%
|
Modulus - Divides left hand operand by
right hand operand and returns remainder
|
B % A will give 0
|
|
++
|
Increment - Increase the value of
operand by 1
|
B++ gives 21
|
|
--
|
Decrement - Decrease the value of
operand by 1
|
B-- gives 19
|
2. The Relational
Operators:
There
are following relational operators supported by Java language
Assume
variable A holds 10 and variable B holds 20 then:
|
Operator
|
Description
|
Example
|
|
==
|
Checks if the value of two operands
are equal or not, if yes then condition becomes true.
|
(A == B) is not true.
|
|
!=
|
Checks if the value of two operands
are equal or not, if values are not equal then condition becomes true.
|
(A != B) is true.
|
|
>
|
Checks if the value of left operand is
greater than the value of right operand, if yes then condition becomes true.
|
(A > B) is not true.
|
|
<
|
Checks if the value of left operand is
less than the value of right operand, if yes then condition becomes true.
|
(A < B) is true.
|
|
>=
|
Checks if the value of left operand is
greater than or equal to the value of right operand, if yes then condition
becomes true.
|
(A >= B) is not true.
|
|
<=
|
Checks if the value of left operand is
less than or equal to the value of right operand, if yes then condition
becomes true.
|
(A <= B) is true.
|
3. The Bitwise
Operators:
Java
defines several bitwise operators which can be applied to the integer types,
long, int, short, char, and byte.
Bitwise
operator works on bits and perform bit by bit operation. Assume if a = 60; and
b = 13; Now in binary format they will be as follows:
a =
0011 1100
b =
0000 1101
-----------------
a&b
= 0000 1100
a|b =
0011 1101
a^b =
0011 0001
~a
= 1100 0011
The
following table lists the bitwise operators:
Assume
integer variable A holds 60 and variable B holds 13 then
|
Operator
|
Description
|
Example
|
|
&
|
Binary AND Operator copies a bit to
the result if it exists in both operands.
|
(A & B) will give 12 which is 0000
1100
|
|
|
|
Binary OR Operator copies a bit if it
exists in eather operand.
|
(A | B) will give 61 which is 0011
1101
|
|
^
|
Binary XOR Operator copies the bit if
it is set in one operand but not both.
|
(A ^ B) will give 49 which is 0011 0001
|
|
~
|
Binary Ones Complement Operator is
unary and has the efect of 'flipping' bits.
|
(~A ) will give -60 which is 1100 0011
|
|
<<
|
Binary Left Shift Operator. The left
operands value is moved left by the number of bits specified by the right
operand.
|
A << 2 will give 240 which is
1111 0000
|
|
>>
|
Binary Right Shift Operator. The left
operands value is moved right by the number of bits specified by the right
operand.
|
A >> 2 will give 15 which is
1111
|
|
>>>
|
Shift right zero fill operator. The
left operands value is moved right by the number of bits specified by the
right operand and shifted values are filled up with zeros.
|
A >>>2 will give 15 which is
0000 1111
|
4. The Logical
Operators:
The
following table lists the logical operators:
Assume
boolean variables A holds true and variable B holds false then:
|
Operator
|
Description
|
Example
|
|
&&
|
Called Logical AND operator. If both
the operands are non zero then then condition becomes true.
|
(A && B) is false.
|
|
||
|
Called Logical OR Operator. If any of
the two operands are non zero then then condition becomes true.
|
(A || B) is true.
|
|
!
|
Called Logical NOT Operator. Use to
reverses the logical state of its operand. If a condition is true then
Logical NOT operator will make false.
|
!(A && B) is true.
|
5. The Assignment
Operators:
There
are following assignment operators supported by Java language:
|
Operator
|
Description
|
Example
|
|
=
|
Simple assignment operator, Assigns
values from right side operands to left side operand
|
C = A + B will assigne value of A + B
into C
|
|
+=
|
Add AND assignment operator, It adds
right operand to the left operand and assign the result to left operand
|
C += A is equivalent to C = C + A
|
|
-=
|
Subtract AND assignment operator, It
subtracts right operand from the left operand and assign the result to left
operand
|
C -= A is equivalent to C = C – A
|
|
*=
|
Multiply AND assignment operator, It
multiplies right operand with the left operand and assign the result to left
operand
|
C *= A is equivalent to C = C * A
|
|
/=
|
Divide AND assignment operator, It
divides left operand with the right operand and assign the result to left
operand
|
C /= A is equivalent to C = C / A
|
|
%=
|
Modulus AND assignment operator, It
takes modulus using two operands and assign the result to left operand
|
C %= A is equivalent to C = C % A
|
|
<<=
|
Left shift AND assignment operator
|
C <<= 2 is same as C = C
<< 2
|
|
>>=
|
Right shift AND assignment operator
|
C >>= 2 is same as C = C
>> 2
|
|
&=
|
Bitwise AND assignment operator
|
C &= 2 is same as C = C & 2
|
|
^=
|
bitwise exclusive OR and assignment
operator
|
C ^= 2 is same as C = C ^ 2
|
|
|=
|
bitwise inclusive OR and assignment
operator
|
C |= 2 is same as C = C | 2
|
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