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<html><head><META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chained Subexpressions</title><link href="../docbook.css" rel="stylesheet" type="text/css"><meta content="DocBook XSL Stylesheets V1.65.0" name="generator"><link rel="home" href="index.html" title="OGNL Language Guide"><link rel="up" href="basicExpressions.html" title="Chapter 4. Expressions"><link rel="previous" href="paren.html" title="Parenthetical Expressions"><link rel="next" href="collectionConstruction.html" title="Collection Construction"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table summary="Navigation header" width="100%"><tr><th align="center" colspan="3">Chained Subexpressions</th></tr><tr><td align="left" width="20%"><a accesskey="p" href="paren.html"><img src="../images/navigation/prev.gif" alt="Prev"></a> </td><th align="center" width="60%">Chapter 4. Expressions</th><td align="right" width="20%"> <a accesskey="n" href="collectionConstruction.html"><img src="../images/navigation/next.gif" alt="Next"></a></td></tr></table><hr></div><div class="section" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="chainedSubexpressions"></a>Chained Subexpressions</h2></div></div><div></div></div><p>If you use a parenthetical expression after a dot, the object that is current at the dot is used as the current object throughout the parenthetical expression. For example,</p><pre class="programlisting">headline.parent.(ensureLoaded(), name)</pre><p>traverses through the <span class="property">headline</span> and <span class="property">parent</span> properties, ensures that the <span class="property">parent</span> is loaded and then returns (or sets) the parent's <span class="property">name</span>.</p><p>Top-level expressions can also be chained in this way. The result of the expression is the right-most expression element.</p><pre class="programlisting">ensureLoaded(), name</pre><p>This will call <tt class="function">ensureLoaded()</tt> on the root object, then get the <span class="property">name</span> property of the root object as the result of the expression.</p></div><div class="navfooter"><hr><table summary="Navigation footer" width="100%"><tr><td align="left" width="40%"><a accesskey="p" href="paren.html"><img src="../images/navigation/prev.gif" alt="Prev"></a> </td><td align="center" width="20%"><a accesskey="u" href="basicExpressions.html"><img src="../images/navigation/up.gif" alt="Up"></a></td><td align="right" width="40%"> <a accesskey="n" href="collectionConstruction.html"><img src="../images/navigation/next.gif" alt="Next"></a></td></tr><tr><td valign="top" align="left" width="40%">Parenthetical Expressions </td><td align="center" width="20%"><a accesskey="h" href="index.html"><img src="../images/navigation/home.gif" alt="Home"></a></td><td valign="top" align="right" width="40%"> Collection Construction</td></tr></table></div></body></html>⌨️ 快捷键说明
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