<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ --> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>Creating a classdef Class (GNU Octave (version 5.1.0))</title> <meta name="description" content="Creating a classdef Class (GNU Octave (version 5.1.0))"> <meta name="keywords" content="Creating a classdef Class (GNU Octave (version 5.1.0))"> <meta name="resource-type" content="document"> <meta name="distribution" content="global"> <meta name="Generator" content="makeinfo"> <link href="index.html#Top" rel="start" title="Top"> <link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> <link href="classdef-Classes.html#classdef-Classes" rel="up" title="classdef Classes"> <link href="Properties.html#Properties" rel="next" title="Properties"> <link href="classdef-Classes.html#classdef-Classes" rel="prev" title="classdef Classes"> <style type="text/css"> <!-- a.summary-letter {text-decoration: none} blockquote.indentedblock {margin-right: 0em} blockquote.smallindentedblock {margin-right: 0em; font-size: smaller} blockquote.smallquotation {font-size: smaller} div.display {margin-left: 3.2em} div.example {margin-left: 3.2em} div.lisp {margin-left: 3.2em} div.smalldisplay {margin-left: 3.2em} div.smallexample {margin-left: 3.2em} div.smalllisp {margin-left: 3.2em} kbd {font-style: oblique} pre.display {font-family: inherit} pre.format {font-family: inherit} pre.menu-comment {font-family: serif} pre.menu-preformatted {font-family: serif} pre.smalldisplay {font-family: inherit; font-size: smaller} pre.smallexample {font-size: smaller} pre.smallformat {font-family: inherit; font-size: smaller} pre.smalllisp {font-size: smaller} span.nolinebreak {white-space: nowrap} span.roman {font-family: initial; font-weight: normal} span.sansserif {font-family: sans-serif; font-weight: normal} ul.no-bullet {list-style: none} --> </style> <link rel="stylesheet" type="text/css" href="octave.css"> </head> <body lang="en"> <a name="Creating-a-classdef-Class"></a> <div class="header"> <p> Next: <a href="Properties.html#Properties" accesskey="n" rel="next">Properties</a>, Up: <a href="classdef-Classes.html#classdef-Classes" accesskey="u" rel="up">classdef Classes</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> </div> <hr> <a name="Creating-a-classdef-Class-1"></a> <h4 class="subsection">34.6.1 Creating a <code>classdef</code> Class</h4> <p>A very basic <code>classdef</code> value class (see <a href="Value-Classes-vs_002e-Handle-Classes.html#Value-Classes-vs_002e-Handle-Classes">Value Classes vs. Handle Classes</a>) is defined by: </p> <div class="example"> <pre class="example">classdef some_class properties endproperties methods endmethods endclassdef </pre></div> <p>In contrast to old style classes, the <code>properties</code>-<code>endproperties</code> block as well as the <code>methods</code>-<code>endmethods</code> block can be used to define properties and methods of the class. Because both blocks are empty, they can be omitted in this particular case. </p> <p>For simplicity, a more advanced implementation of a <code>classdef</code> class is shown using the <code>polynomial</code> example again (see <a href="Creating-a-Class.html#Creating-a-Class">Creating a Class</a>): </p> <div class="example"> <pre class="verbatim">classdef polynomial2 properties poly = 0; endproperties methods function p = polynomial2 (a) if (nargin > 1) print_usage (); endif if (nargin == 1) if (isa (a, "polynomial2")) p.poly = a.poly; elseif (isreal (a) && isvector (a)) p.poly = a(:).'; # force row vector else error ("polynomial2: A must be a real vector"); endif endif endfunction function disp (p) a = p.poly; first = true; for i = 1 : length (a); if (a(i) != 0) if (first) first = false; elseif (a(i) > 0 || isnan (a(i))) printf (" +"); endif if (a(i) < 0) printf (" -"); endif if (i == 1) printf (" %.5g", abs (a(i))); elseif (abs (a(i)) != 1) printf (" %.5g *", abs (a(i))); endif if (i > 1) printf (" X"); endif if (i > 2) printf (" ^ %d", i - 1); endif endif endfor if (first) printf (" 0"); endif printf ("\n"); endfunction endmethods endclassdef </pre></div> <p>An object of class <code>polynomial2</code> is created by calling the class constructor: </p> <div class="example"> <pre class="example">>> p = polynomial2 ([1, 0, 1]) ⇒ p = 1 + X ^ 2 </pre></div> </body> </html>