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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.

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View syllabusR playground

17,534+ codders enrolled

78 lessons69 challenges434 quiz questions

  • Beginner friendly
  • sparkles iconAI-assisted coding help
  • hint iconHands-on interactive lessons
  • volume On iconAudio narration on every lesson
  • quiz iconQuizzes to test your knowledge
  • certificate iconFree certificate of completion

Syllabus

1 sections2 projects78 lessons69 challenges434 quiz questions
  1. Section 1

    Fundamentals

    Start sectionStartExpandCollapse    Build a strong foundation with essential concepts and basic skills78 lessons69 challenges434 questions2 projects

    Introduction to R

    3 lessons316

    Variables and Data Types

    8 lessons656

    Operators Part 1

    5 lessons534

    Operators Part 2

    5 lessons534

    Decision Making

    4 lessons426

    Basic IO

    7 lessons741

    Bill Split Calculator

    Project5 lessons1

    Loops

    8 lessons849

    Functions

    6 lessons633

    FizzBuzz with a Twist

    Project4 lessons1

    Vectors

    7 lessons742

    Iterating Over Sequences

    4 lessons433

    Vectors Advanced

    4 lessons436

    Lists in R

    5 lessons534

    Final Challenges

    3 lessons3

R courses

Hands-on R courses, free to start in your browser.

Interview PreparationData StructuresGraph Algorithms Courses

Beginner Challenges - Practice Basic Concepts

Popular

Put your beginner coding knowledge to test and try to solve this programming challenges, use any language you want, Happy Coding!

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Certificate on completion

  • 20
  • 20

Coding Problems

Popular

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 icon

Certificate on completion

  • 32
  • 31

Stack - Data Structures Series #1

In 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!

Data Structures
  • 13
  • 6
  • 1

Coding Problems: Volume 2

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. This course is an extension of the first Coding Problems

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Certificate on completion

  • 25
  • 24

Hash Tables - Data Structures Series #4

In this course, you will learn about the Hash Table data structure, create a Hash Table from zero using your preferred language, and practice coding challenges with it!

Data Structures
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Certificate on completion

  • 14
  • 12

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!

Data Structures
certificate icon

Certificate on completion

  • 14
  • 6
  • 1
See all 44 R courses →
What you get
Everything you'll use to learn to code

Learn by Doing

Write real code, query databases, build websites, and master AI prompts. Our interactive lessons cover every skill modern developers need.

playground.js
Code Editor
1const greeting = "Hello, Coddy!"
2function sayHi(name) {
3    return greeting + " " + name
4}
5
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Input
"Alex"
Output
"Hello, Coddy! Alex"

Build Your Coding 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!

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Double or Nothing

Day 5 of 7

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Streak Freeze

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Code Anywhere, Anytime

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.

Python
7Streak
250Score
5Energy
Variables
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CONTINUE
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Journey
Goals
Leaderboard
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Rating

You're Not Alone in This

Compete on global leaderboards, invite friends to earn rewards, and celebrate each other's wins. Coding is better with friends!

Challenger League
Challenger LeagueTop 7 advance
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Alex7+ Days
2840
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Jordan7+ Days
2650
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Sam7+ Days
2420
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Casey
2180
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Morgan7+ Days
1950
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Every 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.

Intro to Variables
Audio

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.

1xSarah

Prove Your Skills

Earn certificates for every course you complete. Add them to your LinkedIn profile and resume to showcase your coding expertise to employers.

CoddyCertificate of Completion
This certifies thatJohn Doehas successfully completed
PythonPython Fundamentals
Verified
DateJan 2026
LinkedInAdd to LinkedIn

Why 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.
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Learn R with Coddy

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