Null Object Design Pattern

What is Null Object Design Pattern?

It falls under behavioral design pattern.
It replaces “null” check.
Traditional method: null check for every value which has some limitations in code flow. If we follow “Null object design pattern” then we can get over that hurdle.
The default behavior for objects which has “null” or “nothing.
The null object class is the default implementation.
It would be handy if we want some special flow for something which has nothing or null value.
Example: Spam classification.

Real Life Examples of Null Object Design Pattern

Example 1:

UML Class Diagram of Null Object Design Pattern

Null Object Design Pattern Java Implementation

Step 1:

public class Voltage
{

    private int voltage;

    public Voltage(int v)
    {
        this.voltage = v;
    }

    public int getVolts()
    {
        return voltage;
    }

    public void setVolts(int voltage)
    {
        this.voltage = voltage;
    }

}

Tutorial Videos of Null Object Design Pattern

For tutorial videos, please check out the premium Software Design Pattern course on Udemy.