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<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"/><meta name="viewport" content="width=device-width, initial-scale=0.8"/><title>2.1 Simple Values</title><link rel="stylesheet" type="text/css" href="../scribble.css" title="default"/><link rel="stylesheet" type="text/css" href="icons.css" title="default"/><link rel="stylesheet" type="text/css" href="../racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-style.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../doc-site.css" title="default"/><script type="text/javascript" src="../scribble-common.js"></script><script type="text/javascript" src="../manual-racket.js"></script><script type="text/javascript" src="../manual-racket.js"></script><script type="text/javascript" src="../doc-site.js"></script><script type="text/javascript" src="../local-redirect/local-redirect.js"></script><script type="text/javascript" src="../local-redirect/local-user-redirect.js"></script><!--[if IE 6]><style type="text/css">.SIEHidden { overflow: hidden; }</style><![endif]--></head><body id="doc-racket-lang-org"><div class="tocset"><div class="tocview"><div class="tocviewlist tocviewlisttopspace"><div class="tocviewtitle"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,"tocview_0");">►</a></td><td></td><td><a href="index.html" class="tocviewlink" data-pltdoc="x">The Racket Guide</a></td></tr></table></div><div class="tocviewsublisttop" style="display: none;" id="tocview_0"><table cellspacing="0" cellpadding="0"><tr><td align="right">1 </td><td><a href="intro.html" class="tocviewlink" data-pltdoc="x">Welcome to Racket</a></td></tr><tr><td align="right">2 </td><td><a href="to-scheme.html" class="tocviewselflink" data-pltdoc="x">Racket Essentials</a></td></tr><tr><td align="right">3 </td><td><a href="datatypes.html" class="tocviewlink" data-pltdoc="x">Built-<wbr></wbr>In Datatypes</a></td></tr><tr><td align="right">4 </td><td><a href="scheme-forms.html" class="tocviewlink" data-pltdoc="x">Expressions and Definitions</a></td></tr><tr><td align="right">5 </td><td><a href="define-struct.html" class="tocviewlink" data-pltdoc="x">Programmer-<wbr></wbr>Defined Datatypes</a></td></tr><tr><td align="right">6 </td><td><a href="modules.html" class="tocviewlink" data-pltdoc="x">Modules</a></td></tr><tr><td align="right">7 </td><td><a href="contracts.html" class="tocviewlink" data-pltdoc="x">Contracts</a></td></tr><tr><td align="right">8 </td><td><a href="i_o.html" class="tocviewlink" data-pltdoc="x">Input and Output</a></td></tr><tr><td align="right">9 </td><td><a href="regexp.html" class="tocviewlink" data-pltdoc="x">Regular Expressions</a></td></tr><tr><td align="right">10 </td><td><a href="control.html" class="tocviewlink" data-pltdoc="x">Exceptions and Control</a></td></tr><tr><td align="right">11 </td><td><a href="for.html" class="tocviewlink" data-pltdoc="x">Iterations and Comprehensions</a></td></tr><tr><td align="right">12 </td><td><a href="match.html" class="tocviewlink" data-pltdoc="x">Pattern Matching</a></td></tr><tr><td align="right">13 </td><td><a href="classes.html" class="tocviewlink" data-pltdoc="x">Classes and Objects</a></td></tr><tr><td align="right">14 </td><td><a href="units.html" class="tocviewlink" data-pltdoc="x">Units</a></td></tr><tr><td align="right">15 </td><td><a href="reflection.html" class="tocviewlink" data-pltdoc="x">Reflection and Dynamic Evaluation</a></td></tr><tr><td align="right">16 </td><td><a href="macros.html" class="tocviewlink" data-pltdoc="x">Macros</a></td></tr><tr><td align="right">17 </td><td><a href="languages.html" class="tocviewlink" data-pltdoc="x">Creating Languages</a></td></tr><tr><td align="right">18 </td><td><a href="concurrency.html" class="tocviewlink" data-pltdoc="x">Concurrency and Synchronization</a></td></tr><tr><td align="right">19 </td><td><a href="performance.html" class="tocviewlink" data-pltdoc="x">Performance</a></td></tr><tr><td align="right">20 </td><td><a href="parallelism.html" class="tocviewlink" data-pltdoc="x">Parallelism</a></td></tr><tr><td align="right">21 </td><td><a href="running.html" class="tocviewlink" data-pltdoc="x">Running and Creating Executables</a></td></tr><tr><td align="right">22 </td><td><a href="More_Libraries.html" class="tocviewlink" data-pltdoc="x">More Libraries</a></td></tr><tr><td align="right">23 </td><td><a href="dialects.html" class="tocviewlink" data-pltdoc="x">Dialects of Racket and Scheme</a></td></tr><tr><td align="right">24 </td><td><a href="other-editors.html" class="tocviewlink" data-pltdoc="x">Command-<wbr></wbr>Line Tools and Your Editor of Choice</a></td></tr><tr><td align="right"></td><td><a href="doc-bibliography.html" class="tocviewlink" data-pltdoc="x">Bibliography</a></td></tr><tr><td align="right"></td><td><a href="doc-index.html" class="tocviewlink" data-pltdoc="x">Index</a></td></tr></table></div></div><div class="tocviewlist"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,"tocview_1");">▼</a></td><td>2 </td><td><a href="to-scheme.html" class="tocviewlink" data-pltdoc="x">Racket Essentials</a></td></tr></table><div class="tocviewsublistbottom" style="display: block;" id="tocview_1"><table cellspacing="0" cellpadding="0"><tr><td align="right">2.1 </td><td><a href="Simple_Values.html" class="tocviewselflink" data-pltdoc="x">Simple Values</a></td></tr><tr><td align="right">2.2 </td><td><a href="syntax-overview.html" class="tocviewlink" data-pltdoc="x">Simple Definitions and Expressions</a></td></tr><tr><td align="right">2.3 </td><td><a href="Lists__Iteration__and_Recursion.html" class="tocviewlink" data-pltdoc="x">Lists, Iteration, and Recursion</a></td></tr><tr><td align="right">2.4 </td><td><a href="Pairs__Lists__and_Racket_Syntax.html" class="tocviewlink" data-pltdoc="x">Pairs, Lists, and Racket Syntax</a></td></tr></table></div></div></div></div><div class="maincolumn"><div class="main"><div class="navsettop"><span class="navleft"><form class="searchform"><input class="searchbox" id="searchbox" type="text" tabindex="1" placeholder="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, "8.6", "../");"/></form> <a href="https://docs.racket-lang.org/index.html" title="up to the documentation top" data-pltdoc="x" onclick="return GotoPLTRoot("8.6");">top</a><span class="tocsettoggle"> <a href="javascript:void(0);" title="show/hide table of contents" onclick="TocsetToggle();">contents</a></span></span><span class="navright"> <a href="to-scheme.html" title="backward to "2 Racket Essentials"" data-pltdoc="x">← prev</a> <a href="to-scheme.html" title="up to "2 Racket Essentials"" data-pltdoc="x">up</a> <a href="syntax-overview.html" title="forward to "2.2 Simple Definitions and Expressions"" data-pltdoc="x">next →</a></span> </div><h4 x-source-module="(lib "scribblings/guide/guide.scrbl")" x-source-pkg="racket-doc" x-part-tag=""Simple_Values"">2.1<tt> </tt><a name="(part._.Simple_.Values)"></a>Simple Values</h4><p>Racket values include numbers, booleans, strings, and byte strings. In
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DrRacket and documentation examples (when you read the documentation
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in color), value expressions are shown in green.</p><p><span style="font-style: italic">Numbers</span> are written in the usual way, including fractions
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and imaginary numbers:</p><blockquote class="refpara"><blockquote class="refcolumn"><blockquote class="refcontent"><p><span class="imageleft"><img src="finger.png" alt="+" width="24" height="24"/></span><a href="numbers.html" data-pltdoc="x">Numbers</a> (later in this guide) explains more about numbers.</p></blockquote></blockquote></blockquote><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktVal">1</span><span class="hspace"> </span><span class="RktVal">3.14</span></td></tr><tr><td><span class="RktVal">1/2</span><span class="hspace"> </span><span class="RktVal">6.02e+23</span></td></tr><tr><td><span class="RktVal">1+2i</span><span class="hspace"> </span><span class="RktVal">9999999999999999999999</span></td></tr></table></blockquote><p><span style="font-style: italic">Booleans</span> are <span class="RktVal">#t</span> for true and <span class="RktVal">#f</span> for
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false. In conditionals, however, all non-<span class="RktVal">#f</span> values are
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treated as true.</p><blockquote class="refpara"><blockquote class="refcolumn"><blockquote class="refcontent"><p><span class="imageleft"><img src="finger.png" alt="+" width="24" height="24"/></span><a href="booleans.html" data-pltdoc="x">Booleans</a> (later in this guide) explains more about booleans.</p></blockquote></blockquote></blockquote><p><span style="font-style: italic">Strings</span> are written between doublequotes. Within a string,
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backslash is an escaping character; for example, a backslash followed
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by a doublequote includes a literal doublequote in the string. Except
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for an unescaped doublequote or backslash, any Unicode character can
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appear in a string constant.</p><blockquote class="refpara"><blockquote class="refcolumn"><blockquote class="refcontent"><p><span class="imageleft"><img src="finger.png" alt="+" width="24" height="24"/></span><a href="strings.html" data-pltdoc="x">Strings (Unicode)</a> (later in this guide) explains more about strings.</p></blockquote></blockquote></blockquote><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktVal">"Hello, world!"</span></td></tr><tr><td><span class="RktVal">"Benjamin \"Bugsy\" Siegel"</span></td></tr><tr><td><span class="RktVal">"λx:(μα.α→α).xx"</span></td></tr></table></blockquote><p>When a constant is evaluated in the <a href="intro.html#%28tech._repl%29" class="techoutside" data-pltdoc="x"><span class="techinside">REPL</span></a>, it typically prints the same
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as its input syntax. In some cases, the printed form is a normalized
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version of the input syntax. In documentation and in DrRacket’s <a href="intro.html#%28tech._repl%29" class="techoutside" data-pltdoc="x"><span class="techinside">REPL</span></a>,
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results are printed in blue instead of green to highlight the
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difference between an input expression and a printed result.</p><p><div class="SIntrapara">Examples:</div><div class="SIntrapara"><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">> </span><span class="RktVal">1.0000</span></td></tr><tr><td><p><span class="RktRes">1.0</span></p></td></tr><tr><td><span class="stt">> </span><span class="RktVal">"Bugs \u0022Figaro\u0022 Bunny"</span></td></tr><tr><td><p><span class="RktRes">"Bugs \"Figaro\" Bunny"</span></p></td></tr></table></blockquote></div></p><div class="navsetbottom"><span class="navleft"><form class="searchform"><input class="searchbox" id="searchbox" type="text" tabindex="1" placeholder="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, "8.6", "../");"/></form> <a href="https://docs.racket-lang.org/index.html" title="up to the documentation top" data-pltdoc="x" onclick="return GotoPLTRoot("8.6");">top</a><span class="tocsettoggle"> <a href="javascript:void(0);" title="show/hide table of contents" onclick="TocsetToggle();">contents</a></span></span><span class="navright"> <a href="to-scheme.html" title="backward to "2 Racket Essentials"" data-pltdoc="x">← prev</a> <a href="to-scheme.html" title="up to "2 Racket Essentials"" data-pltdoc="x">up</a> <a href="syntax-overview.html" title="forward to "2.2 Simple Definitions and Expressions"" data-pltdoc="x">next →</a></span> </div></div></div><div id="contextindicator"> </div></body></html> |