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<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>Raku essentials</title> <meta property="og:title" content="Raku essentials" /> <meta property="og:locale" content="en_US" /> <meta property="og:site_name" content="The Complete Course of the Raku programming language" /> <link rel="stylesheet" href="/assets/main.css"> <link rel="stylesheet" href="/assets/course.css?t=5"> <title>Raku essentials</title> <link rel="apple-touch-icon" sizes="57x57" href="/assets/apple-icon-57x57.png"> <link rel="apple-touch-icon" sizes="60x60" href="/assets/apple-icon-60x60.png"> <link rel="apple-touch-icon" sizes="72x72" href="/assets/apple-icon-72x72.png"> <link rel="apple-touch-icon" sizes="76x76" href="/assets/apple-icon-76x76.png"> <link rel="apple-touch-icon" sizes="114x114" href="/assets/apple-icon-114x114.png"> <link rel="apple-touch-icon" sizes="120x120" href="/assets/apple-icon-120x120.png"> <link rel="apple-touch-icon" sizes="144x144" href="/assets/apple-icon-144x144.png"> <link rel="apple-touch-icon" sizes="152x152" href="/assets/apple-icon-152x152.png"> <link rel="apple-touch-icon" sizes="180x180" href="/assets/apple-icon-180x180.png"> <link rel="icon" type="image/png" sizes="192x192" href="/assets/android-icon-192x192.png"> <link rel="icon" type="image/png" sizes="32x32" href="/assets/favicon-32x32.png"> <link rel="icon" type="image/png" sizes="96x96" href="/assets/favicon-96x96.png"> <link rel="icon" type="image/png" sizes="16x16" href="/assets/favicon-16x16.png"> <link rel="manifest" href="/assets/manifest.json"> <meta name="msapplication-TileColor" content="#ffffff"> <meta name="msapplication-TileImage" content="/assets/ms-icon-144x144.png"> <meta name="theme-color" content="#ffffff"> </head> <body> <div class="container-lg px-3 my-5 markdown-body"> <main class="page-content" aria-label="Content"> <div class="wrapper"> <a href="/">Course of Raku</a> <h1 id="raku-essentials">Raku essentials</h1> <h2 id="part-1-raku-essentials">Part 1. Raku essentials</h2> <h4 id="basic-introduction-to-raku-and-its-compiler">Basic introduction to Raku and its compiler</h4> <ul> <li><a href="/essentials/what-is-raku">What is Raku</a></li> <li><a href="/essentials/raku-vs-rakudo">Raku vs. Rakudo</a></li> <li><a href="/essentials/how-to-install-rakudo">How to install Rakudo</a></li> <li><a href="/essentials/editors-and-ides">Editors and IDEs</a></li> <li><a href="/essentials/conventional-file-extensions">Conventional file extensions</a></li> <li><a href="/essentials/hello-world">Hello, World!</a></li> <li><a href="/essentials/on-unicode">Notes on using Unicode</a></li> <li><a href="/essentials/running-programs">Running programs</a> — <a href="/essentials/running-programs/exercises"> 1 exercise</a> <ul> <li><a href="/essentials/running-programs/from-command-line">Running from command line</a></li> <li><a href="/essentials/running-programs/from-repl">Running from REPL</a></li> <li><a href="/essentials/running-programs/from-ide">Running from IDE</a></li> <li><a href="/essentials/running-programs/using-docker">Using docker</a></li> <li><a href="/essentials/running-programs/using-online-services">Using online services</a></li> </ul> </li> <li><a href="/essentials/simple-input-output">Simple input and output</a> <ul> <li><a href="/essentials/simple-input-output/say">Output with <code class="language-plaintext highlighter-rouge">say</code></a></li> <li><a href="/essentials/simple-input-output/prompt">Input with <code class="language-plaintext highlighter-rouge">prompt</code></a></li> </ul> </li> <li><a href="/essentials/comments">Comments</a> <ul> <li><a href="/essentials/comments/single-line">Single-line comments</a> — <a href="/essentials/comments/single-line#practice"> 1 quiz</a></li> <li><a href="/essentials/comments/multi-line">Multi-line comments</a></li> <li><a href="/essentials/comments/embedded">Embedded comments</a></li> </ul> </li> </ul> <h4 id="variables-and-data-types-essentials">Variables and data types essentials</h4> <ul> <li><a href="/essentials/scalar-variables">Scalar variables</a> — <a href="/essentials/scalar-variables/exercises"> 4 exercises</a> <ul> <li><a href="/essentials/scalar-variables/declaring-a-variable">Declaring a variable</a> — <a href="/essentials/scalar-variables/declaring-a-variable#practice"> 2 quizzes</a></li> <li><a href="/essentials/scalar-variables/assigning-a-value">Assigning a value</a> — <a href="/essentials/scalar-variables/assigning-a-value#practice"> 2 quizzes</a></li> <li><a href="/essentials/scalar-variables/declaration-with-initialization">Declaration with initialization</a> — <a href="/essentials/scalar-variables/declaration-with-initialization#practice"> 2 quizzes</a></li> <li><a href="/essentials/scalar-variables/defined-or-operator">The defined-or operator</a></li> <li><a href="/essentials/scalar-variables/identifiers">Names of the variables</a> — <a href="/essentials/scalar-variables/identifiers#practice"> 1 quiz</a></li> </ul> </li> <li><a href="/essentials/strings">Strings</a> — <a href="/essentials/strings#practice"> 1 quiz</a> and <a href="/essentials/strings/exercises"> 4 exercises</a> <ul> <li><a href="/essentials/strings/string-concatenation">String concatenation</a> — <a href="/essentials/strings/string-concatenation#practice"> 3 quizzes</a></li> <li><a href="/essentials/strings/variable-interpolation">Variable interpolation</a> — <a href="/essentials/strings/variable-interpolation#practice"> 1 quiz</a></li> <li><a href="/essentials/strings/code-interpolation">Code interpolation</a></li> <li><a href="/essentials/strings/escaping-special-characters">Escaping special characters</a> — <a href="/essentials/strings/escaping-special-characters#practice"> 1 quiz</a></li> <li><a href="/essentials/strings/string-length">String length</a> — <a href="/essentials/strings/string-length#practice"> 1 quiz</a></li> </ul> </li> <li><a href="/essentials/numbers">Numbers</a> — <a href="/essentials/numbers/exercises"> 7 exercises</a> <ul> <li><a href="/essentials/numbers/integers">Integer numbers</a> — <a href="/essentials/numbers/integers#practice"> 2 quizzes</a></li> <li><a href="/essentials/numbers/rats">Rational numbers</a> — <a href="/essentials/numbers/rats#practice"> 1 quiz</a></li> <li><a href="/essentials/numbers/numeric">Floating-point numbers</a></li> <li><a href="/essentials/numbers/operations">Operations with numbers</a></li> </ul> </li> <li><a href="/essentials/booleans">Boolean type</a> — <a href="/essentials/booleans#practice"> 1 quiz</a> and <a href="/essentials/booleans/exercises"> 3 exercises</a> <ul> <li><a href="/essentials/booleans/operations">Boolean operations</a> — <a href="/essentials/booleans/operations#practice"> 1 quiz</a></li> <li><a href="/essentials/booleans/boolean-operations-other-types">Boolean operations with other types</a> — <a href="/essentials/booleans/boolean-operations-other-types#practice"> 1 quiz</a></li> </ul> </li> <li><a href="/essentials/ranges">Ranges</a> — <a href="/essentials/ranges/exercises"> 1 exercise</a> <ul> <li><a href="/essentials/ranges/excluding-endpoints">Excluding endpoints</a> — <a href="/essentials/ranges/excluding-endpoints#practice"> 1 quiz</a></li> <li><a href="/essentials/ranges/matching-against-a-range">Matching against a range</a> — <a href="/essentials/ranges/matching-against-a-range#practice"> 1 quiz</a></li> </ul> </li> </ul> <h4 id="control-flow-essentials">Control flow essentials</h4> <ul> <li><a href="/essentials/code-blocks">Code blocks</a> <ul> <li><a href="/essentials/code-blocks/lexical-scope">Lexical scope</a> — <a href="/essentials/code-blocks/lexical-scope#practice"> 1 quiz</a></li> <li><a href="/essentials/code-blocks/global-variables">Global variables</a> — <a href="/essentials/code-blocks/global-variables#practice"> 1 quiz</a></li> <li><a href="/essentials/code-blocks/local-variables">Local variables</a> — <a href="/essentials/code-blocks/local-variables#practice"> 1 quiz</a></li> </ul> </li> <li><a href="/essentials/conditional-checks">Conditional checks</a> — <a href="/essentials/conditional-checks/exercises"> 4 exercises</a> <ul> <li><a href="/essentials/conditional-checks/if"><code class="language-plaintext highlighter-rouge">if</code> blocks</a> — <a href="/essentials/conditional-checks/if#practice"> 1 quiz</a></li> <li><a href="/essentials/conditional-checks/else"><code class="language-plaintext highlighter-rouge">else</code> blocks</a></li> <li><a href="/essentials/conditional-checks/elsif">Using <code class="language-plaintext highlighter-rouge">elsif</code></a> — <a href="/essentials/conditional-checks/elsif#practice"> 1 quiz</a></li> <li><a href="/essentials/conditional-checks/unless">Using <code class="language-plaintext highlighter-rouge">unless</code></a></li> <li><a href="/essentials/conditional-checks/modifiers"><code class="language-plaintext highlighter-rouge">if</code> and <code class="language-plaintext highlighter-rouge">unless</code> as statement modifiers</a></li> <li><a href="/essentials/conditional-checks/comparing-numbers">Comparing numbers</a> — <a href="/essentials/conditional-checks/comparing-numbers#practice"> 1 quiz</a></li> <li><a href="/essentials/conditional-checks/comparing-strings">Comparing strings</a> — <a href="/essentials/conditional-checks/comparing-strings#practice"> 2 quizzes</a></li> <li><a href="/essentials/conditional-checks/ternary-operator">Ternary operator</a> — <a href="/essentials/conditional-checks/ternary-operator#practice"> 1 quiz</a></li> </ul> </li> <li><a href="/essentials/loops">Loops</a> — <a href="/essentials/loops/exercises"> 7 exercises</a> <ul> <li><a href="/essentials/loops/while">Using <code class="language-plaintext highlighter-rouge">while</code></a> — <a href="/essentials/loops/while#practice"> 1 quiz</a></li> <li><a href="/essentials/loops/until">Using <code class="language-plaintext highlighter-rouge">until</code></a> — <a href="/essentials/loops/until#practice"> 1 quiz</a></li> <li><a href="/essentials/loops/repeat">Using <code class="language-plaintext highlighter-rouge">repeat</code></a> — <a href="/essentials/loops/repeat#practice"> 1 quiz</a></li> <li><a href="/essentials/loops/modifiers"><code class="language-plaintext highlighter-rouge">while</code> and <code class="language-plaintext highlighter-rouge">until</code> as statement modifiers</a></li> <li><a href="/essentials/loops/loop">Three-statement <code class="language-plaintext highlighter-rouge">loop</code></a></li> <li><a href="/essentials/loops/infinite-loops">Infinite loops</a></li> <li><a href="/essentials/loops/for"><code class="language-plaintext highlighter-rouge">for</code> loops</a> — <a href="/essentials/loops/for#practice"> 1 quiz</a></li> <li><a href="/essentials/loops/topic">Topic variable</a></li> <li><a href="/essentials/loops/postfix-for">Postfix form of <code class="language-plaintext highlighter-rouge">for</code></a> — <a href="/essentials/loops/postfix-for#practice"> 1 quiz</a></li> </ul> </li> </ul> <h4 id="more-about-types">More about types</h4> <ul> <li><a href="/essentials/coercion">Data type conversion</a> — <a href="/essentials/coercion#practice"> 1 quiz</a> and <a href="/essentials/coercion/exercises"> 3 exercises</a> <ul> <li><a href="/essentials/coercion/what">Introspection with <code class="language-plaintext highlighter-rouge">WHAT</code></a> — <a href="/essentials/coercion/what#practice"> 1 quiz</a></li> <li><a href="/essentials/coercion/methods">Converting types using type coercion methods</a></li> <li><a href="/essentials/coercion/new">Converting types using constructor forms</a></li> <li><a href="/essentials/coercion/prefixes">Converting types with prefix operators</a></li> </ul> </li> <li><a href="/essentials/typed-variables">Typed variables</a> — <a href="/essentials/typed-variables/exercises"> 4 exercises</a> <ul> <li><a href="/essentials/typed-variables/type-constraints">Type constraints</a> — <a href="/essentials/typed-variables/type-constraints#practice"> 1 quiz</a></li> <li><a href="/essentials/typed-variables/using-of">Using <code class="language-plaintext highlighter-rouge">of</code></a></li> <li><a href="/essentials/typed-variables/coercion">Type conversion for typed variables</a> — <a href="/essentials/typed-variables/coercion#practice"> 1 quiz</a></li> <li><a href="/essentials/typed-variables/allomorphs">Allomorphs</a></li> </ul> </li> <li><a href="/essentials/positionals">Positional data types</a> — <a href="/essentials/positionals/exercises"> 9 exercises</a> <ul> <li><a href="/essentials/positionals/arrays">Arrays</a> — <a href="/essentials/positionals/arrays#practice"> 1 quiz</a></li> <li><a href="/essentials/positionals/nested-arrays">Nested arrays</a> — <a href="/essentials/positionals/nested-arrays#practice"> 1 quiz</a></li> <li><a href="/essentials/positionals/args-array">The <code class="language-plaintext highlighter-rouge">@*ARGS</code> array</a> — <a href="/essentials/positionals/args-array#practice"> 1 quiz</a></li> <li><a href="/essentials/positionals/interpolating-arrays">Interpolating arrays</a> — <a href="/essentials/positionals/interpolating-arrays#practice"> 1 quiz</a></li> <li><a href="/essentials/positionals/lists">Lists</a> — <a href="/essentials/positionals/lists#practice"> 1 quiz</a></li> <li><a href="/essentials/positionals/quoting-string-arrays">Quoting string arrays</a> — <a href="/essentials/positionals/quoting-string-arrays#practice"> 2 quizzes</a></li> <li><a href="/essentials/positionals/subscripting-ranges">Subscripting ranges</a> — <a href="/essentials/positionals/subscripting-ranges#practice"> 1 quiz</a></li> </ul> </li> <li><a href="/essentials/associatives">Associative data types</a> — <a href="/essentials/associatives/exercises"> 6 exercises</a> <ul> <li><a href="/essentials/associatives/pairs">Pairs</a> — <a href="/essentials/associatives/pairs#practice"> 1 quiz</a></li> <li><a href="/essentials/associatives/hashes">Hashes</a> — <a href="/essentials/associatives/hashes#practice"> 2 quizzes</a></li> <li><a href="/essentials/associatives/nested-hashes">Nested hashes</a> — <a href="/essentials/associatives/nested-hashes#practice"> 1 quiz</a></li> <li><a href="/essentials/associatives/interpolating-hashes">Interpolating hashes</a> — <a href="/essentials/associatives/interpolating-hashes#practice"> 1 quiz</a></li> </ul> </li> </ul> <h4 id="functions-essentials">Functions essentials</h4> <ul> <li><a href="/essentials/functions">Creating and calling functions</a> — <a href="/essentials/functions#practice"> 1 quiz</a> and <a href="/essentials/functions/exercises"> 6 exercises</a> <ul> <li><a href="/essentials/functions/identifiers">Function names</a> — <a href="/essentials/functions/identifiers#practice"> 1 quiz</a></li> <li><a href="/essentials/functions/function-parameters">Function parameters</a> — <a href="/essentials/functions/function-parameters#practice"> 2 quizzes</a></li> <li><a href="/essentials/functions/return-result">Returning the result</a> — <a href="/essentials/functions/return-result#practice"> 1 quiz</a></li> <li><a href="/essentials/functions/positional-parameters">Positional parameters</a> — <a href="/essentials/functions/positional-parameters#practice"> 1 quiz</a></li> <li><a href="/essentials/functions/named-parameters">Named parameters</a> — <a href="/essentials/functions/named-parameters#practice"> 2 quizzes</a></li> <li><a href="/essentials/functions/default-values">Default values</a> — <a href="/essentials/functions/default-values#practice"> 2 quizzes</a></li> </ul> </li> <li><a href="/essentials/more-on-functions">More about functions</a> — <a href="/essentials/more-on-functions/exercises"> 1 exercise</a> <ul> <li><a href="/essentials/more-on-functions/mind-the-space">Mind the space</a></li> <li><a href="/essentials/more-on-functions/typed-parameters">Typed parameters</a> — <a href="/essentials/more-on-functions/typed-parameters#practice"> 1 quiz</a></li> <li><a href="/essentials/more-on-functions/return-type">Return type</a> — <a href="/essentials/more-on-functions/return-type#practice"> 1 quiz</a></li> <li><a href="/essentials/more-on-functions/multi-functions">Multi-functions</a> — <a href="/essentials/more-on-functions/multi-functions#practice"> 3 quizzes</a></li> </ul> </li> <li><a href="/essentials/built-in-functions-for-printing">Built-in functions for printing</a> — <a href="/essentials/built-in-functions-for-printing/exercises"> 2 exercises</a> <ul> <li><a href="/essentials/built-in-functions-for-printing/say"><code class="language-plaintext highlighter-rouge">say</code></a></li> <li><a href="/essentials/built-in-functions-for-printing/print"><code class="language-plaintext highlighter-rouge">print</code></a></li> <li><a href="/essentials/built-in-functions-for-printing/put"><code class="language-plaintext highlighter-rouge">put</code></a></li> <li><a href="/essentials/built-in-functions-for-printing/note"><code class="language-plaintext highlighter-rouge">note</code></a></li> </ul> </li> <li><a href="/essentials/the-main-function">The <code class="language-plaintext highlighter-rouge">MAIN</code> function</a> — <a href="/essentials/the-main-function/exercises"> 3 exercises</a> <ul> <li><a href="/essentials/the-main-function/reading-command-line-arguments">Reading command-line arguments</a> — <a href="/essentials/the-main-function/reading-command-line-arguments#practice"> 2 quizzes</a></li> <li><a href="/essentials/the-main-function/multi-main-functions">Multiple <code class="language-plaintext highlighter-rouge">MAIN</code> functions</a> — <a href="/essentials/the-main-function/multi-main-functions#practice"> 1 quiz</a></li> <li><a href="/essentials/the-main-function/using-unit-sub">Using <code class="language-plaintext highlighter-rouge">unit sub</code></a> — <a href="/essentials/the-main-function/using-unit-sub#practice"> 1 quiz</a></li> </ul> </li> </ul> <div style="margin-top: 2em; border-top: 1px solid lightgray; padding-top: 2em; font-size: 80%;"> Translations of this page: English • <a href="/de/essentials/">Deutsch</a> • <a href="/es/essentials/">Español</a> • <a href="/it/essentials/">Italiano</a> • <a href="/lv/essentials/">Latviešu</a> • <a href="/nl/essentials/">Nederlands</a> • <a href="/bg/essentials/">Български</a> • <a href="/ru/essentials/">Русский</a> • <a href="/uk/essentials/">Українська</a> </div> </div> </main> </div> </body> </html>