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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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16,685+ codders enrolled

  • 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 lessons68 challenges434 quiz questions
  1. Section 1

    Fundamentals

    Start sectionStartExpandCollapse    Build a strong foundation with essential concepts and basic skills78 lessons68 challenges434 questions2 projects

    Introduction to R

    3 lessons216
    • 01What is R?Challenge
    • 02Hello WorldChallengeQuiz
    • 03Comments in RQuiz

    Variables and Data Types

    8 lessons656
    • 01Numeric Data TypeChallengeQuiz
    • 02Integer Data TypeQuiz
    • 03Character Data TypeChallengeQuiz
    • 04Logical Data TypeChallengeQuiz
    • 05Checking Data TypesChallengeQuiz
    • 06Naming ConventionsQuiz
    • 07Missing Values: NAChallengeQuiz
    • 08Recap - Variable CreationChallenge

    Operators Part 1

    5 lessons534
    • 01Arithmetic OperatorsChallengeQuiz
    • 02Integer Division and ModuloChallengeQuiz
    • 03Assignment OperatorsChallengeQuiz
    • 04Recap - Simple MathChallenge
    • 05Comparison OperatorsChallengeQuiz

    Operators Part 2

    5 lessons534
    • 01Logical Operators (AND, OR)ChallengeQuiz
    • 02Logical Operators Part 2 (NOT)ChallengeQuiz
    • 03Recap - Simple LogicChallenge
    • 04Vectorized Logic Part 1ChallengeQuiz
    • 05Vectorized Logic Part 2ChallengeQuiz

    Decision Making

    4 lessons426
    • 01If StatementChallengeQuiz
    • 02If - ElseChallengeQuiz
    • 03Recap - Simple CalculatorChallenge
    • 04Nested If - ElseChallengeQuiz

    Basic IO

    7 lessons741
    • 01Print OutputChallengeQuiz
    • 02Cat for OutputChallengeQuiz
    • 03Output With VariablesChallengeQuiz
    • 04Reading Input with readline()ChallengeQuiz
    • 05Type Conversion BasicsChallengeQuiz
    • 06Recap - Age CalculatorChallenge
    • 07Recap - True or FalseChallenge

    Bill Split Calculator

    Project5 lessons1
    • 01Welcome MessageChallenge
    • 02Getting User InputProject
    • 03Calculating The Tip And TotalProject
    • 04Splitting The BillProject
    • 05Formatted Output (sprintf)Project

    Loops

    8 lessons849
    • 01For LoopChallengeQuiz
    • 02While LoopChallengeQuiz
    • 03BreakChallengeQuiz
    • 04Next (Continue)ChallengeQuiz
    • 05Recap - FactorialChallenge
    • 06Sequence Generation (seq, :)ChallengeQuiz
    • 07Nested LoopsChallengeQuiz
    • 08Recap - Dynamic InputChallenge

    Functions

    6 lessons633
    • 01Declaring a FunctionChallengeQuiz
    • 02Function ArgumentsChallengeQuiz
    • 03Return ValuesChallengeQuiz
    • 04Recap - Sigma FunctionChallenge
    • 05Recap - Validation FunctionChallenge
    • 06Default Parameter ValuesChallengeQuiz

    FizzBuzz with a Twist

    Project4 lessons1
    • 01Game OverviewChallenge
    • 02The FizzBuzz FunctionProject
    • 03Looping Through NumbersProject
    • 04Adding The TwistProject

    Vectors

    7 lessons742
    • 01Creating Vectors with c()ChallengeQuiz
    • 02Accessing Vector ElementsChallengeQuiz
    • 03Modifying VectorsChallengeQuiz
    • 04Vector OperationsChallengeQuiz
    • 05Recap - Price VectorChallenge
    • 06Recap - Reversed VectorChallenge
    • 07Named VectorsChallengeQuiz

    Iterating Over Sequences

    4 lessons433
    • 01Iterating Over Vector ElementsChallengeQuiz
    • 02Using seq_along()ChallengeQuiz
    • 03Iterating Characters (strsplitChallengeQuiz
    • 04String Manipulation FunctionsChallengeQuiz

    Vectors Advanced

    4 lessons436
    • 01Vector Slicing and IndexingChallengeQuiz
    • 02Logical IndexingChallengeQuiz
    • 03Vector Arithmetic & RecyclingChallengeQuiz
    • 04The %in% OperatorChallengeQuiz

    Lists in R

    5 lessons534
    • 01Creating ListsChallengeQuiz
    • 02Accessing List ElementsChallengeQuiz
    • 03Modifying ListsChallengeQuiz
    • 04Named ListsChallengeQuiz
    • 05Recap - Product ListChallenge

    Final Challenges

    3 lessons3
    • 01Flat Asterisk PyramidChallenge
    • 02Pattern FinderChallenge
    • 03What To BuyChallenge

R courses

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

Data Structures

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!

certificate icon

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

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

certificate icon

Certificate on completion

  • 25
  • 24

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

Heaps & Priority Queues - Data Structures Series #7

New

In this course, you will learn about the Heap data structure (the backbone of priority queues), create a MinHeap from zero using your preferred language, and practice coding challenges with it!

Data Structures
certificate icon

Certificate on completion

  • 14
  • 6
  • 1

Star Pattern Bootcamp

Put your programming problem solving skills to learn how to print star patterns range from simple to complex, involving different levels of nested loops, conditional statements, and mathematical calculations.

  • 30
  • 28
See all 28 R courses →

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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