Java I/O Operation – Wrapper Class vs Primitive Class Variables

It is better to use the Primitive Class variable for the I/O operation unless there is a necessity of using the Wrapper Class. In this article, we can discuss briefly both wrapper class and primitive data type.

• A primitive data type focuses on variable values, without any additional methods.
• The Default value of Primitive class variables are given below,

Primitive Data types	Default values
int	0
byte	0
short	0
char	\u0000 or null
boolean	false
double	0.0
float	0.0

• The default value of the wrapper class is null as they are objects.
• Primitive classes are faster when compared to wrapper classes. However, the wrapper class allows null values but the primitive class does not allow any null values.
• Wrapper classes help the Java program be completely object-oriented whereas primitive data types help in the simple declaration of values with variables. They also help the code be serializable.
• For conversion of primitive data type to objects, wrapper class is used. We can see the conversion of the Primitive data type to objects using the code below,

Java

/*package whatever //do not write package name here */

import java.io.*;
class GFG {
    public static void main(String[] args)
    {
        // primitive data type
        int n = 15;

        // Creating object from primitive data type
        Integer obj = Integer.valueOf(n);
        System.out.println(n + " " + obj);
    }
}

Output:

15 15

• If we have to serialize a primitive value, it must first be converted into objects using wrapper classes. 
• Wrapper classes help in working with Collection variables.

Primitive data Type	Wrapper Class
Even Large scale calculations can be made faster	When collections are used, a wrapper class is required
Methods will return a value	Methods will return null
mostly used when the variable should not be null or ‘\0’	Used when the variable should be null

• For knowing more about the usage of primitive data type to wrapper class, we need to focus on Autoboxing and Unboxing.
• We can convert a Wrapper Class into primitive data types is called Unboxing.

Java

/*package whatever //do not write package name here */

import java.io.*;

class GFG {
    public static void main(String[] args)
    {
        // wrapper class to primitive datatype
        Integer a = new Integer(6);
        // Unboxing
        int b = a;
        System.out.print(b);
    }
}

Output:

6

• We can also refer to the below-mentioned code of converting the primitive data type to wrapper class (Autoboxing).

Java

/*package whatever //do not write package name here */

import java.io.*;

class GFG {
    public static void main(String[] args)
    {
        // converting primitive data type to wrapper class
        int a = 6;
        // Autoboxing
        Integer b = Integer.valueOf(a);
        System.out.println(b);
    }
}

Output:

6