what are the wrapper classes in java code example

Example 1: wrapper classes in java ebhor.com

public class CommandLineArguments {
    public static void main(String[] args) {
        int a = Integer.parseInt(args[0]);
        int b = Integer.parseInt(args[1]);
        int sum = a + b;
        System.out.println("Sum is " + sum);
    }
}

Example 2: primitive vs wrapper classes in java

Differences: 
				1. Wrappers classes are object 
				2. null can only be assigned to classes
				3. Wrapper class does have methods
				4. Primitives does have default values
						default value of primitives:  
								 byte, short, int, long ==> 0
								 float, double ==> 0.0;
								 boolean ==> false;
								 char ==> space		 
				5. Default values of wrapper class: null