Primitive Data Types
- Eclipse: Oxygen
- Java: 1.8
Java supports eight primitive data types. These are the basic and predefined data type of the programming language. Java determines the size of each primitive data types, it cannot be changed. Primitive data types are represented by reserved keywords.
The primitive data type is divided into the following categories:
- Integer data type.
- Floating Point data type.
- Boolean data type.
- Char data type.
Integer data type
Integer data type is used to store integer numbers (number without a decimal point). The minimum and maximum value that a datatype can store depends on the size of the data type.
The range of Integer data types
The following table lists represent the all integer data types, their storage requirements in bytes and the numeric range they support.
Types | Size | Minimum value | Maximum Value |
byte | 8 bit/1byte | -128 | 127 |
short | 16bit/2byte | -32768 | 32767 |
int | 32 bit/4byte | -2,147,483,648 | 2,147,483,647 |
long | 64 bit/8byte | -9,223,372,036,854,775,808 | 9,223,372,036,854,775,807 |
- Depending upon the requirement we must choose the appropriate data type.
byte
The size of the byte type is 8bit/1byte. The minimum value of the byte is -128 and the maximum value is 127.
short
The short data type is integer compatible data type and used to contain integer value or an integer number. The size of the short type is 16bit/2byte. The minimum value of the short is -32768 and the maximum value is 32767.
int
The size of the int value is 32bit/4byte. The minimum value of int is -2147483648 and the maximum range is 2147483647.
long
The size of the long data type is 64bit/8byte. While declaring long data type always use suffix “L” by default Java considered it as an integer. Java is a case-sensitive language so it is recommended use “L” in upper case.
Initialization of long variable:
long longMax = 9223372036854775807L;
long longMin = -9223372036854775808L;
- L specifies that value is a long.
Floating Point data type
Floating point variables are used to deal with decimal value. There are two types of floating point data types. The following table gives you details about floating point types with storage sizes and ranges of values with their precision.
Type | Storage size | Value range | Precision |
Float | 4 byte | 1.2E-38 to 3.4E+38 | 7 decimal places |
Double | 8 byte | 2.3E-308 to 1.7E+308 | 16 decimal places |
In the program, whenever we want to store a floating-point value in a variable, we can use one of these data types accordingly.
Float–float is used for floating-point (decimal) values, it occupies 32-bit memory
Initialization of float variable:
1 |
float var = 9.0f; |
- f specifies that value is a float.
Precision in float:
1 2 3 4 |
public static void main(String[] args) { float var = 10f / 6f; System.out.println(var); } |
Output:
1.6666666
Double – double is used for high precision floating-point values, it occupies 64-bit memory
Initialization of double variable:
1 |
double var = 9.5d; |
- d specifies that the value is double.
Precision in double data type is more than a float data type.
Precision in double:
1 2 3 4 |
public static void main(String[] args) { double var = 10d / 6d; System.out.println (var); } |
Output:
1.6666666666666667
Boolean
Boolean is a data type that represents one bit of information either true or false.
1 2 3 4 |
public static void main(String[] args) { boolean var = true; System.out.println (var); } |
Output: true
Char
A char data type is a single-length entity. This could be an alphabet, a digit, or a symbol. It is also used to hold the Unicode for symbols. Value for char should be with single quotes.
1 2 3 4 5 6 |
public static void main(String[] args) { char var = '\u00A7'; char var1 = 'A'; System.out.println (var); System.out.println (var1); } |
Output:
§
A
Note: We must only use the single quotes pointing to left
- The length should be one.
- Single quote point to the left should be used
- Any character on the keyboard is allowed
Example: ‘A’,’*’,’1’
Contributed by: Poonam Tomar