Identifying classes from requirements in LLD - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the first step in identifying classes from requirements?

The first step is to carefully read and understand the requirements to find important nouns and noun phrases that represent potential classes.

beginner

Why are nouns in requirements important for identifying classes?

Nouns often represent objects, entities, or concepts in the system, which can be modeled as classes in the design.

intermediate

What role do verbs play when identifying classes from requirements?

Verbs help identify behaviors or methods that classes should have, showing what actions the classes can perform.

intermediate

How can you differentiate between a class and an attribute when analyzing requirements?

If the noun represents something with its own identity and behavior, it is likely a class; if it describes a property of a class, it is an attribute.

advanced

What is a common technique to validate identified classes from requirements?

Use scenarios or use cases to check if the classes and their interactions make sense and cover the required functionality.

Which of the following is most likely a class in a library management system?

A Read

B Borrowed

C Quickly

D Book

Book is a noun representing an entity, suitable as a class. 'Borrowed' is a verb form, 'Quickly' is an adverb, and 'Read' is a verb.

When identifying classes, what should you do with nouns that represent simple properties?

A Model them as attributes of classes

B Ignore them completely

C Treat them as separate classes

D Convert them into methods

Simple properties should be modeled as attributes of classes, not as separate classes.

Which of these is NOT a good indicator of a class in requirements?

A Person

B Transaction

C Calculate

D Account

'Calculate' is a verb indicating an action, not a class.

What is the best way to confirm if identified classes are correct?

A Ignore requirements and guess

B Use scenarios or use cases to test them

C Add as many classes as possible

D Only use nouns without verbs

Using scenarios or use cases helps validate if classes and their interactions fulfill requirements.

Which of the following is a behavior that might belong to a class?

A Withdraw money

B Name

C Age

D Balance

'Withdraw money' is an action or method, while the others are attributes.

Explain the process of identifying classes from a set of system requirements.

Think about how nouns and verbs in sentences relate to objects and actions.

Describe how you would differentiate between a class and an attribute when analyzing requirements.

Consider if the noun can stand alone as an object or just describes something else.