In Java, the term “type” refers to the data type of a variable or an expression. It specifies the kind of data that a variable can hold or the type of value that an expression evaluates to. Java is a statically-typed language, meaning that the data types are known at compile-time, and each variable must be declared with a specific type.

Java has two main categories of types:

1. Primitive Types: These are the basic data types built into the Java language. They are not objects and do not have methods associated with them. There are eight primitive types in Java:

   • byte: 8-bit signed integer.
   • short: 16-bit signed integer.
   • int: 32-bit signed integer.
   • long: 64-bit signed integer.
   • float: 32-bit floating-point number.
   • double: 64-bit floating-point number.
   • char: 16-bit Unicode character.
   • boolean: Represents a true or false value.

   Example variable declarations:

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   int age = 30;
double pi = 3.14159;
char initial = 'J';
boolean isStudent = true;


2. Reference Types: These types refer to objects in memory. They include classes, interfaces, arrays, and enums. Reference types have methods associated with them because they are objects. When declaring a variable of a reference type, the variable holds a reference to the actual object in memory rather than directly storing the value.

   Example variable declarations:

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   String name = "John";
ArrayList<Integer> numbers = new ArrayList<>();
MyClass obj = new MyClass();


Java also allows the use of type inference, known as “var” in local variable declarations. When “var” is used, the compiler automatically infers the type based on the value assigned to the variable:

It’s essential to understand types in Java, as they determine how memory is allocated and how values can be manipulated in your programs.