<?xml version="1.0" encoding="utf-8" ?> <!-- for emacs: -*- coding: utf-8 -*- --> <!-- Apache may like this line in the file .htaccess: AddCharset utf-8 .html --> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN" "http://www.w3.org/2002/04/xhtml-math-svg/xhtml-math-svg-flat.dtd" > <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"> <head><title>if -- condition testing</title> <link rel="stylesheet" type="text/css" href="../../../../Macaulay2/Style/doc.css"/> </head> <body> <table class="buttons"> <tr> <td><div><a href="___Ignore__Example__Errors.html">next</a> | <a href="_identity.html">previous</a> | <a href="___Ignore__Example__Errors.html">forward</a> | <a href="_identity.html">backward</a> | up | <a href="index.html">top</a> | <a href="master.html">index</a> | <a href="toc.html">toc</a> | <a href="http://www.math.uiuc.edu/Macaulay2/">Macaulay2 web site</a></div> </td> </tr> </table> <hr/> <div><h1>if -- condition testing</h1> <div class="single"><h2>Description</h2> <div><tt>if p then x else y</tt> computes <tt>p</tt>, which must yield the value <a href="_true.html" title="">true</a> or <a href="_false.html" title="">false</a>. If true, then the value of <tt>x</tt> is provided, else the value of <tt>y</tt> is provided.<p/> <tt>if p then x</tt> computes <tt>p</tt>, which must yield the value <a href="_true.html" title="">true</a> or <a href="_false.html" title="">false</a>. If true, then the value of <tt>x</tt> is provided, else <a href="_null.html" title="the unique member of the empty class">null</a> is provided.</div> </div> <div class="waystouse"><h2>For the programmer</h2> <p>The object <a href="_if.html" title="condition testing">if</a> is <span>a <a href="___Keyword.html">keyword</a></span>.</p> </div> </div> </body> </html>