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    Primitive Data Type                            Non-Primitive Data Type
                         There are 8 Primitive data types.                There are mainly 4 types of non-Primitive data
                                                                          types.

                         To use them “new” operator is not required.      Use of “new” operator is mandatory for
                                                                          creating instances.
                         The size of a primitive type depends  on the  Size of non-primitive types may vary.
                         data type.

                         Primitive data  types hold only single values.   The non-primitive data types are used to store
                                                                          the group of values.

                     VARIABLE

                     A variable is a name given to a space in computer memory to store a value. In other words, it is a reference
                     to a memory location where data is held. The term "variable" comes from the combination of "vary" and
                     "able," meaning its value can change during the program's execution. Variables can take different values
                     at various points, depending on the logic of the program. You might be wondering, what is the difference
                     between an identifier and a variable. An identifier is a name used to uniquely identify an entity (such as
                     a function, class or variable) in the program. It is a general term that encompasses variables, functions,
                     constants and more. On the other hand, a variable is a specific type of identifier that refers to a memory
                     location used to store data that can change as the program runs.

                     Declaring a Variable

                     Before using a variable in Java, it must first be declared. If a variable is not declared, it cannot be used
                     and attempting to do so will result in a compile-time error.

                     The syntax for declaring a variable is as follows:

                     <data type> <name of the variable>;
                     Where, the <data type> specifies any primitive or non-primitive data type and the name of the variable
                     should be a valid Java identifier. For example, int age; Here, int is the data type and the age is the
                     variable name.  As you know, that every statement is terminated with the help of a semicolon. Similarly,
                     the declaration statement is also terminated by using a semicolon.

                     For example:

                     int age;
                     Here, int is the data type and age is the variable name.

                     You can also declare multiple variables of the same type in a single statement, separating them with
                     commas.

                     For example:

                     int age, marks;

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