Cohesion

Cohesion

In this tutorial, we are going to discuss Cohesion in Java. For every component we have to define a well defined single purpose. Such type of components are said to be followed high “cohesion”.

In Java, cohesion refers to the degree to which the elements within a module (such as a class) belong together. High cohesion implies that the elements within the module are closely related and focused on performing a specific set of tasks, while low cohesion implies that the elements are more loosely related and may perform a variety of unrelated tasks.

In object-oriented design, cohesion refers all about how a single class is designed. Cohesion is the Object-Oriented principle most closely associated with ensuring that a class is designed with a single, well-focused purpose.

E.g

Suppose we have a class that multiply two numbers, but the same class creates a pop-up window displaying the result. This is an example of a low cohesive class because the window and the multiplication operation don’t have much in common.

To make it high cohesive, we would have to create a class Display and a class Multiply. The Display will call Multiply’s method to get the result and display it. This way to develop a high cohesive solution.

class Multiply {
    int a = 5;
    int b = 5;
    public int multiply(int a, int b)
    {
        this.a = a;
        this.b = b;
        return a * b;
    }
} 
  
class Display {
    public static void main(String[] args)
    {
        Multiply m = new Multiply();
        System.out.println(m.multiply(5, 5));
    }
}

The main advantages of High Cohesion are:

1. It improves maintainability.
2. Enhancements is easy.
3. Promotes reusability.

Note

• High cohesion is when you have a class that does a well-defined job. Low cohesion is when a class does a lot of jobs that don’t have much in common.
• High cohesion gives us better-maintaining facility and Low cohesion results in monolithic classes that are difficult to maintain, understand and reduce re-usability.

That’s all about Cohesion in Java. If you have any queries or feedback, please write us email at contact@waytoeasylearn.com. Enjoy learning, Enjoy Java.!