Register to get access to free programming courses with interactive exercises

About course JS: Building abstractions with data

Abstraction is the primary way to handle complexity in programming. It allows you to escape the implementation details and focus on the essentials.

A good abstraction example is the array sort function. It doesn't matter how it's implemented; what matters is that it leads to the result we're interested in.

Another example is higher-order functions, such as map, filter, and reduce, which allow you to process collections without thinking about what goes on under the hood. Collections even don't have to be flat; you can build such functions for any complex structures, such as trees. And due to this abstraction, we can focus on the processing itself rather than the data traversal technicalities.

On the other hand, the data itself often has a complex structure. Representing a user in an unconventional system may require defining dozens or hundreds of different parameters and the associated data. In situations like this, it's a good idea to hide this structure behind a set of functions, which cover the internal complexity and simplify code support. This is called data-driven abstraction.

In this course, we'll learn some basic principles of program design, and how to model and represent objects from the real (and imaginary) world via a program. We'll design a library for working with graphical primitives, such as points, segments, and shapes. This library is lucid enough for everyone to understand (even visually), and it's pretty handy to express with code.

Main course subjects:

  • Subject area
  • Ontology
  • Level design (abstraction barriers)
  • Invariants

Are there any more questions? Ask them in the Discussion section.

The Hexlet support team or other students will answer you.

About Hexlet learning process

For full access to the course you need a professional subscription.

A professional subscription will give you full access to all Hexlet courses, projects and lifetime access to the theory of lessons learned. You can cancel your subscription at any time.

Get access
130
courses
1000
exercises
2000+
hours of theory
3200
tests

Sign up

Programming courses for beginners and experienced developers. Start training for free

  • 130 courses, 2000+ hours of theory
  • 1000 practical tasks in a browser
  • 360 000 students
By sending this form, you agree to our Personal Policy and Service Conditions

Our graduates work in companies:

<span class="translation_missing" title="translation missing: en.web.courses.lessons.registration.bookmate">Bookmate</span>
<span class="translation_missing" title="translation missing: en.web.courses.lessons.registration.healthsamurai">Healthsamurai</span>
<span class="translation_missing" title="translation missing: en.web.courses.lessons.registration.dualboot">Dualboot</span>
<span class="translation_missing" title="translation missing: en.web.courses.lessons.registration.abbyy">Abbyy</span>
Suggested learning programs
profession
Development of front-end components for web applications
10 months
from scratch
Start at any time

Use Hexlet to the fullest extent!

  • Ask questions about the lesson
  • Test your knowledge in quizzes
  • Practice in your browser
  • Track your progress

Sign up or sign in

By sending this form, you agree to our Personal Policy and Service Conditions
Toto Image

Ask questions if you want to discuss a theory or an exercise. Hexlet Support Team and experienced community members can help find answers and solve a problem.