Java Interview Guide : 200+ Interview Questions and Answers - What is Cohesion?

The video discusses the concept of cohesion in software design, emphasizing the importance of having highly cohesive classes where responsibilities are closely related. An example of a class with low cohesion is analyzed, highlighting its multiple unrelated responsibilities. The video then proposes a solution by dividing responsibilities into separate classes, each handling a specific task, such as downloading, parsing, and storing data. This approach leads to better cohesion and more maintainable code. The video concludes by discussing how organizing classes in this manner results in highly cohesive applications.

What does cohesion in a class refer to?

• How related the responsibilities of a class are

• The speed at which a class executes

• The amount of data a class can handle

• The number of methods in a class

Why is the 'download and store' class considered to have low cohesion?

• It is too complex to understand

• It has too few methods

• It uses too many external libraries

• It handles multiple unrelated responsibilities

Which of the following is NOT a responsibility of the 'download and store' class?

• Storing data into a database

• Parsing data

• Rendering data on a webpage

• Downloading data from the Internet

How can cohesion be improved in the 'download and store' example?

• By reducing the number of lines of code

• By splitting responsibilities into separate classes

• By adding more methods to the class

• By using a different programming language

What is the main responsibility of the 'Internet downloader' class?

• Rendering data on a webpage

• Downloading data from the Internet

• Storing data into a database

• Parsing data

What is the benefit of having a 'database storer' class?

• It can handle multiple types of databases

• It focuses solely on storing data into a database

• It can parse and store data simultaneously

• It reduces the need for a database

What is the role of the 'download and store' class in a high cohesion design?

• To parse data from the Internet

• To directly interact with the database

• To create instances of other classes and coordinate their actions

• To handle all responsibilities related to data processing