In this section we will tell you about data type in java. A data type is defined as " type of data that can be stored in variable". Java is a statically-typed language that means before using the variable it must be declared.
Data type in java
In this section we will tell you about data type in java. A data type is defined as " type of data that can be stored in variable". Java is a statically-typed language that means before using the variable it must be declared. Declaring a variable includes type of variable and name of variable. By declaring the type of data, compiler restrict the user from assigning a wrong type of data to a variable.
int counter = 1;
By doing so, we are informing compiler that variable "counter" is holding the integer type of data, which has an initial value 1.
There are two data type in java.
- Primitive Data type
- Reference Data type
Primitive Data type :
Apart from int type there are seven other primitive data types in java programming language. Primitive means which is predefined by the language. 8 primitive data type are as follows:
byte : byte data type is a 8-bit signed two's compliment integer. It has minimum value of -128 and maximum value of 128. It is used when save space in large array. Default value is 0.
short : short data type is 16-bit signed two's compliment integer. It has minimum value of -32768 and maximum value is +32767, it is used to save memory in large array. Default value is 0.
int : int data type is 32-bit signed two's compliment integer. It has minimum value of -2,147,483648 and maximum value is +2,147,483647, it is used to as default data type. Default value is 0.
long : long data type is 64-bit signed two's compliment integer. It has minimum value of -9,223,372,036,854,775,808 and maximum value is +9,223,372,036,854,775,807.Default values is 0, this data type is used when more than int range is required .
float : float data type is single precision 32-bit IEEE 754 floating point. float is mainly used to save memory in array and default value is 0.0f .
double : double data type is a double precision 64-bit IEEE 754 format. this data type is basically used as default data type for decimal. Default value is 0.0d.
boolean : boolean data type has only two possible values true and false. This data type is used for flag that retern true/false. Default value is false.
char : char data type is single 16-bit Unicode character. It has a minimum value of '\u0000' and maximum value of '\uffff'. char data type is used to store any character.
Reference Data type :
It is also called non-primitive or object type, which are used to access object type.
Class, array and interfaces are reference data type.
Default value of any reference variable is null.
A reference variable can be used to refer to any object of the declared type.