Learn R Programming
A free, interactive online R course. You write R on every lesson, with AI hints when a factor surprises you, and a free certificate when you finish.
22,095+ codders enrolled
199 lessons197 challenges1,111 quiz questions
- Beginner friendly
AI-assisted coding help
Hands-on interactive lessons
Audio narration on every lesson
Quizzes to test your knowledge
Free certificate of completion
Syllabus
Section 1
Fundamentals
Start sectionStartBuild a strong foundation with essential concepts and basic skillsIntroduction to R
3 lessons616Variables and Data Types
8 lessons956Operators Part 1
5 lessons534Operators Part 2
5 lessons534Decision Making
4 lessons425Basic IO
7 lessons741Bill Split Calculator
Project5 lessons5Loops
8 lessons847Functions
6 lessons633FizzBuzz with a Twist
Project4 lessons4Vectors
7 lessons742Iterating Over Sequences
4 lessons433Vectors Advanced
4 lessons436Lists in R
5 lessons534Final Challenges
3 lessons3Section 2
Logic & Flow
Start sectionStartBuild on R Fundamentals with string tools, lookups, sets, matrices, the apply family, sorting and grouping, data frames, advanced control flow and error handling. Apply your skills in Gradebook and Expense Tracker projects, mastery and final challenges.Strings In Depth
6 lessons1140Key-Value Lookups
5 lessons932Sets and Counting
5 lessons932Matrices
5 lessons932Project - Gradebook
Project5 lessons58Functions as Values
5 lessons932The Apply Family
5 lessons932Sorting and Grouping
5 lessons932Data Frames
5 lessons932Advanced Control Flow
5 lessons932Error Handling
5 lessons932Project - Expense Tracker
Project5 lessons58Final Challenges
3 lessons3Section 3
Object Oriented Programming
Start sectionStartModel programs with R's object systems. Learn S3 classes, constructors, generics and inheritance, closures and environments that keep state, S4 classes, generics and validity, Reference Classes and classic design patterns, then build a Library Management project.S3 Basics
6 lessons1140S3 Generics and Methods
5 lessons932S3 Inheritance
5 lessons932Encapsulation in R
5 lessons932S4 Classes
5 lessons932S4 Generics and Methods
5 lessons932S4 Inheritance
5 lessons932Reference Classes
5 lessons932Design Patterns Part 1
4 lessons832Design Patterns Part 2
4 lessons832Project: Library Management
Project5 lessons58Final Challenges
3 lessons3
R courses
Hands-on R courses, free to start in your browser.
Beginner Challenges - Practice Basic Concepts
PopularPut your beginner coding knowledge to test and try to solve this programming challenges, use any language you want, Happy Coding!
Certificate on completion
- 20
- 20
Stack - Data Structures Series #1
PopularIn this course, you will learn about the Stack data structure, create a Stack from zero using your preferred language, and practice coding challenges with it!
- 13
- 11
- 1
Coding Problems
Put your programming problem solving skills to the test using the exercises with different difficulties in this course. Designed for coders with some prior knowledge of the basic syntax in any programming language.
Certificate on completion
- 32
- 31
AVL Tree - Data Structures Series #10
In this course, you will learn about the AVL Tree data structure, build a self-balancing binary search tree from zero in your preferred language, and practice coding challenges with it!
Certificate on completion
- 16
- 14
- 1
Linked List - Data Structures Series #5
In this course, you will learn about the Linked List data structure, create a Linked List from zero using your preferred language, and practice coding challenges with it!
Certificate on completion
- 14
- 12
- 1
Binary Tree - Data Structures Series #3
In this course, you will learn about the Binary Tree data structure, create a Binary Tree from zero using your preferred language, and practice coding challenges with it!
- 13
- 11
- 1
Learn by Doing
Write real code, query databases, build websites, and master AI prompts. Our interactive lessons cover every skill modern developers need.
Build Your Streak
Stay consistent and watch your progress grow! Track your daily coding habit, protect your streak with freeze days, and earn rewards for showing up every day.
12 days streak
Return tomorrow to keep your streak!
January 2026
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Double or Nothing
Day 5 of 7
Streak Freeze
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Code Anywhere
Take your coding journey on the go! No setup, no downloads: just open and start coding. Available on iOS, Android and Web with 4.9 star ratings.
You're Not Alone
Compete on global leaderboards, invite friends to earn rewards, and celebrate each other's wins. Coding is better with friends!
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Promotion zoneEvery way to learn
Read, listen, test yourself, ask the AI, or look up anything you've already covered. Every lesson meets you where you are.
A variable is a named container that stores a value you can reference later in your program.
In Python, you create one by writing the name, an equals sign, then the value you want to store.
The value can change over time. Reassigning the name simply points it to a new value.
Earn a Certificate
Earn certificates for every course you complete. Add them to your LinkedIn profile and resume to showcase your coding expertise to employers.
Certificate of CompletionPython Fundamentals
Add to LinkedInWhy learn R with Coddy
- Run real R code in your browser. No R install, no RStudio setup. Each lesson runs your R script server-side and shows the output, including printed values and basic plots, instantly.
- R as it's actually used for data: vectors and lists, data frames, indexing and filtering, functions, the apply family, basic statistics, and reading and summarizing data. The R foundations every analyst and data scientist needs.
- AI hints help you fix R errors and read cryptic warning messages without spoiling the answer, so common stumbles like factor surprises and recycling rules become learning moments.
- Free R programming certificate when you finish the course. A credible signal for analyst, data-science, and statistical-research roles where R fluency is a baseline expectation.
Frequently asked questions about learning R
Is R hard to learn?
R has a few quirks that throw newcomers - 1-based indexing, vectorized operations, factors - but the core is straightforward, especially for anyone who's worked with spreadsheets before. The course introduces R in small steps with hands-on exercises, so the quirks feel like features rather than traps.
What is R programming used for?
R is the lingua franca of statistics, data analysis, and academic research. Heavily used in bioinformatics, econometrics, social sciences, finance, and any field where you need to load data, run statistical models, and produce charts. The package ecosystem around R (especially the tidyverse and ggplot2) is one of its biggest strengths.
How long does it take to learn R?
R basics - variables, vectors, data frames, basic plotting - take one to two weeks of daily practice. Becoming comfortable with data wrangling, statistical models, and ggplot2 usually takes one to three months. Domain depth (bioinformatics, finance, social science) is then layered on top through real projects.
Should I learn R or Python for data science?
Both work. R was built for statistics and stays unmatched for statistical modeling, academic work, and exploratory analysis. Python is the more general-purpose choice with stronger machine-learning and engineering ecosystems. Many data scientists know both and pick per task; if you're statistics-first, start with R.
Can I learn R online for free?
Yes. The interactive R course is free - full lessons, R coding exercises, quizzes, and a certificate. R runs server-side so you don't need to install R or RStudio locally to start writing code.
Do I get a certificate after the R course?
Yes. Finishing the R programming course gives you a free certificate of completion. A verifiable proof point you can add to your resume or share on LinkedIn alongside any analysis projects or notebooks you've built.
