This content originally appeared on DEV Community and was authored by silambarasan rajendran
1). Primitive Data Types:
The Java programming language is statically-typed, which means that all variables must first be declared before they can be used.
example: int grear = 1;
A primitive type is predefined by the language and is named by a reserved keyword.
Like int, byte, char,…
Primitive values do not share state with other primitive values.
Example: int grear = 1;
boolean grear_bike = true;
int total_output = grear + grear_bike
This is not possible.
byte: The byte data type is an 8-bit signed two’s complement integer.
- 128 to 127. The byte data type can be useful for saving memory in large arrays.
short: The short data type is a 16-bit signed two’s complement integer. It has a minimum value of -32,768 and a maximum value of 32,767 (inclusive). As with byte, the same guidelines apply .
int: By default, the int data type is a 32-bit signed two’s complement integer, which has a minimum value of -231 and a maximum value of 231-1. In Java SE 8 and later, you can use the int data type to represent an unsigned 32-bit integer.
long: The long data type is a 64-bit two’s complement integer. The signed long has a minimum value of -263 and a maximum value of 263-1. In Java SE 8 and later, you can use the long data type to represent an unsigned 64-bit long, which has a minimum value of 0 and a maximum value of 264-1.
float: The float data type is a single-precision 32-bit IEEE 754 floating point. Its range of values is beyond the scope of this discussion, but is specified in the Floating-Point Types, Formats, and Values section of the Java Language Specification.
double: The double data type is a double-precision 64-bit IEEE 754 floating point.
boolean: The boolean data type has only two possible values: true and false. Use this data type for simple flags that track true/false conditions. This data type represents one bit of information, but its “size” isn’t something that’s precisely defined.
char: The char data type is a single 16-bit Unicode character. It has a minimum value of ‘\u0000’ (or 0) and a maximum value of ‘\uffff’ (or 65,535 inclusive).
2). Non-Primitive Data Types:
the Java programming language also provides special support for character strings via the java.lang.String class. Enclosing your character string within double quotes will automatically create a new String object; for example, String s = “this is a string”;. String objects are immutable, which means that once created, their values cannot be changed. The String class is not technically a primitive data type, but considering the special support given to it by the language, you’ll probably tend to think of it as such.
Default Values:
The following chart summarizes the default values for the above data types.
Data Type Default Value (for fields)
byte 0
short 0
int 0
long 0L
float 0.0f
double 0.0d
char ‘\u0000’
String (or any object) null
boolean false
Datatypes also classified Class and Object Specific:
public class Laptop {
int price;
String brand;
boolean fhd;
public static void main(){
Laptop laptop1 = new Laptop();
Laptop laptop2 = new Laptop();
laptop1.price = 35500;
laptop1.brand = "lenova";
laptop2.price = 55435;
laptop2.brand = "dell";
System.out.println("Laptop Price is:" + laptop1.price);
}
}
This content originally appeared on DEV Community and was authored by silambarasan rajendran