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<h2 class="title"><em>parent</em></h2>
<p class="para">
You may find yourself writing code that refers to
variables and functions in base classes. This is
particularly true if your derived class is a refinement
or specialisation of code in your base class.
</p>
<p class="para">
Instead of using the literal name of the base class in your
code, you should be using the special name
<em>parent</em>, which refers to the name of your
base class as given in the <em>extends</em>
declaration of your class. By doing this, you avoid using the
name of your base class in more than one place. Should
your inheritance tree change during implementation, the
change is easily made by simply changing the
<em>extends</em> declaration of your class.
</p>
<div class="informalexample">
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #007700">class </span><span style="color: #0000BB">A </span><span style="color: #007700">{<br /> function </span><span style="color: #0000BB">example</span><span style="color: #007700">() {<br /> echo </span><span style="color: #DD0000">"I am A::example() and provide basic functionality.<br />\n"</span><span style="color: #007700">;<br /> }<br />}<br /><br />class </span><span style="color: #0000BB">B </span><span style="color: #007700">extends </span><span style="color: #0000BB">A </span><span style="color: #007700">{<br /> function </span><span style="color: #0000BB">example</span><span style="color: #007700">() {<br /> echo </span><span style="color: #DD0000">"I am B::example() and provide additional functionality.<br />\n"</span><span style="color: #007700">;<br /> </span><span style="color: #0000BB">parent</span><span style="color: #007700">::</span><span style="color: #0000BB">example</span><span style="color: #007700">();<br /> }<br />}<br /><br /></span><span style="color: #0000BB">$b </span><span style="color: #007700">= new </span><span style="color: #0000BB">B</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">// This will call B::example(), which will in turn call A::example().<br /></span><span style="color: #0000BB">$b</span><span style="color: #007700">-></span><span style="color: #0000BB">example</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
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