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<title>What References Are Not</title>
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<h2 class="title">What References Are Not</h2>
<p class="para">
As said before, references are not pointers. That means, the
following construct won't do what you expect:
<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">function </span><span style="color: #0000BB">foo</span><span style="color: #007700">(&</span><span style="color: #0000BB">$var</span><span style="color: #007700">)<br />{<br /> </span><span style="color: #0000BB">$var </span><span style="color: #007700">=& </span><span style="color: #0000BB">$GLOBALS</span><span style="color: #007700">[</span><span style="color: #DD0000">"baz"</span><span style="color: #007700">];<br />}<br /></span><span style="color: #0000BB">foo</span><span style="color: #007700">(</span><span style="color: #0000BB">$bar</span><span style="color: #007700">); <br /></span><span style="color: #0000BB">?></span>
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</p>
<p class="simpara">
What happens is that <var class="varname"><var class="varname">$var</var></var> in
<var class="varname"><var class="varname">foo</var></var> will be bound with
<var class="varname"><var class="varname">$bar</var></var> in the caller, but then
re-bound with <var class="varname"><var class="varname"><a href="reserved.variables.globals.html" class="classname">$GLOBALS["baz"]</a></var></var>. There's no way
to bind <var class="varname"><var class="varname">$bar</var></var> in the calling scope to something else
using the reference mechanism, since <var class="varname"><var class="varname">$bar</var></var> is not
available in the function <var class="varname"><var class="varname">foo</var></var> (it is represented by
<var class="varname"><var class="varname">$var</var></var>, but <var class="varname"><var class="varname">$var</var></var> has only
variable contents and not name-to-value binding in the calling
symbol table).
You can use <a href="language.references.return.html" class="link">returning
references</a> to reference variables selected by the function.
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