In all languages you play with numbers, characters and different types of data. You always need Variables to store this data, so, every variable is associated with the data type.
In Java, a data type is a way of categorizing different types of information that can be stored in variables. Just like we have different types of containers to store different things, we have different data types to store different types of values in Java.
For example, if we want to store a whole number in a variable, we would use the int data type. If we want to store a decimal number, we would use the double data type. If we want to store a single character, we would use the char data type. By using different data types, we can make sure that the computer knows what kind of value we are storing in a variable, and we can perform operations on that value that are appropriate for its type.
In addition to the built-in data types like int, double, and char, we can also create our own data types using classes and interfaces. Java allows us to store more complex data structures and create our own types of objects.
Java is a strongly-typed language, which means that all variables must be declared with a specific data type before they can be used. This is in contrast to dynamically-typed languages like Python, where variables can change their data type during runtime.
Java has two main categories of data types: primitive data types and non-primitive data types. The primitive data types include boolean, byte, short, int, long, float, double, and char. These data types are built into the Java language and are used to represent basic types of data, such as integers, floating-point numbers, characters, and true/false values.
Non-primitive data types, on the other hand, are created using classes and interfaces. Examples of non-primitive data types in Java include String, Arrays, Classes, and Interfaces. These data types are used to represent more complex data structures, such as collections of objects or user-defined types.
Let’s explorer more about Primitive and Non-Primitive Data Types in Java:
Primitive Data Types :
These are the basic data types provided by the programming language. They have fixed size and have default values like the default value for an int is 0, and for a boolean is false. There are total 8 primitive data types provided by the Java. They are:
Data Type | Size (in Bits) | Default Value | Range of Values |
boolean | 1 | false | true or false |
byte | 8 | 0 | -128 to 127 |
short | 16 | 0 | -32768 to 32767 |
int | 32 | 0 | -2,147,483,648 to 2,147,483,647 |
long | 64 | 0L | -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 |
float | 32 | 0.0f | 1.4E-45 to 3.4028235E38 |
double | 64 | 0.0d | 4.9E-324 to 1.7976931348623157E308 |
char | 16 | ‘\u0000’ | ‘\u0000’ to ‘\uffff’ |
The boolean data type represents true or false values. The byte, short, int, and long data types represent whole numbers of varying sizes. The float and double data types represent floating-point numbers of varying precision. The char data type represents a single character from the Unicode character set.
By using the appropriate data type, we can ensure that variables in our Java program can hold values that are appropriate for their intended purpose. For example, using a byte data type to hold a value between -128 and 127 can save memory compared to using an int data type, which can hold much larger values.
Non Primitive Data Type
Non-primitive data types in Java, unlike primitive data types, are not built-in data types, but are created by the user using classes and interfaces. They are used to represent more complex data structures that require multiple values to be stored together and to define new data types based on existing data types. They also called Reference type.
Here are some common uses of non-primitive data types in Java:
- Arrays: Arrays are a type of non-primitive data type that can be used to store a collection of elements of the same data type. They are useful when you need to store a large number of related values and access them in a systematic way.
- Strings: Strings are a non-primitive data type that represent a sequence of characters. They are used to store text and are often used in input/output operations and in the creation of user interfaces.
- Classes: Classes are a user-defined non-primitive data type that can encapsulate data and behavior. They are used to define new data types and to organize related data and methods into a single unit.
- Interfaces: Interfaces are another user-defined non-primitive data type that define a set of methods that a class must implement. They are used to create a contract between the class and the rest of the program, allowing for flexibility and modularity in code design.
- Collections: Collections are a type of non-primitive data type that can store a collection of objects of any data type. They are used when you need to store a variable number of related values and perform operations on them, such as sorting or searching.
Overall, non-primitive data types are an essential component of Java programming, providing a flexible and powerful way to store and manipulate complex data structures.
Difference between Primitive and Non Primitive data types :
Primitive Data Types | Non Primitive Data Types | |
Definition | These are basic data types provided by the programming language. | These are data types that are not defined by the programming language, but are created by the programmer using classes or interfaces. |
Size | They have fixed sizes. | Their size is not fixed and depends on the amount of data they hold. |
Default Value | They have default values assigned to them. For example, the default value for an int is 0, and for a boolean is false. | They have no default value. If a non-primitive variable is not initialized, it will have a null value. |
Memory Management | They are stored directly in memory. | They are stored indirectly in memory, via references. |
Operations | They support primitive operations, such as arithmetic, comparison, and logical operations. | They do not support primitive operations, but can have methods and functions that operate on them. |
Immutability | They are immutable, meaning that their value cannot be changed once they are created. | They can be mutable, meaning that their value can be changed by modifying the object’s state. |
Examples | int, boolean, double, char | String, Array, Class, Interface |
In conclusion, data types are an important concept in Java programming that allow us to categorize different types of information and store them in variables. There are two main categories of data types in Java – primitive data types and non-primitive data types.
Primitive data types represent simple values, such as whole numbers or floating-point numbers, and are built into the Java language. On the other hand, non-primitive data types are created by the user using classes and interfaces, and allow for more complex data structures and custom data types to be defined.
By using the appropriate data type, we can ensure that our Java programs are efficient and accurate, and that we can perform operations on our data that are appropriate for its type. Whether it’s storing simple values like integers or creating custom data types for more complex applications, understanding data types is essential for any Java programmer.