<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >Iteração de Objetos</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE="Manual do PHP" HREF="index.html"><LINK REL="UP" TITLE="Classes e Objetos (PHP 5)" HREF="language.oop5.html"><LINK REL="PREVIOUS" TITLE="Sobrecarga" HREF="language.oop5.overloading.html"><LINK REL="NEXT" TITLE="Patterns" HREF="language.oop5.patterns.html"><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=UTF-8"></HEAD ><BODY CLASS="sect1" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Manual do PHP</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="language.oop5.overloading.html" ACCESSKEY="P" >Anterior</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Capítulo 19. Classes e Objetos (PHP 5)</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="language.oop5.patterns.html" ACCESSKEY="N" >Próxima</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="sect1" ><H1 CLASS="sect1" ><A NAME="language.oop5.iterations" >Iteração de Objetos</A ></H1 ><P > PHP 5 fornece uma maneira de defini objetos para que seja possível iterar por uma lista de items, com, por exeplo, uma instrução <A HREF="control-structures.foreach.html" >a seção <I ><TT CLASS="literal" >foreach</TT ></I > Capítulo 16</A > . Por padrão, todas as propriedades <A HREF="language.oop5.visibility.html" >visíveis</A > serão usadas para a iteração. </P ><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN5833" ></A ><P ><B >Exemplo 19-21. Simple Object Iteration</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br /></font><font color="#007700">class </font><font color="#0000BB">MyClass<br /></font><font color="#007700">{<br /> </font><font color="#0000BB">public $var1 </font><font color="#007700">= </font><font color="#DD0000">'value 1'</font><font color="#007700">;<br /> </font><font color="#0000BB">public $var2 </font><font color="#007700">= </font><font color="#DD0000">'value 2'</font><font color="#007700">;<br /> </font><font color="#0000BB">public $var3 </font><font color="#007700">= </font><font color="#DD0000">'value 3'</font><font color="#007700">;<br /><br /> </font><font color="#0000BB">protected $protected </font><font color="#007700">= </font><font color="#DD0000">'protected var'</font><font color="#007700">;<br /> </font><font color="#0000BB">private $private </font><font color="#007700">= </font><font color="#DD0000">'private var'</font><font color="#007700">;<br /><br /> function </font><font color="#0000BB">iterateVisible</font><font color="#007700">() {<br /> echo </font><font color="#DD0000">"MyClass::iterateVisible:\n"</font><font color="#007700">;<br /> foreach(</font><font color="#0000BB">$this </font><font color="#007700">as </font><font color="#0000BB">$key </font><font color="#007700">=> </font><font color="#0000BB">$value</font><font color="#007700">) {<br /> print </font><font color="#DD0000">"$key => $value</font><font color="#007700">\n</font><font color="#DD0000">"</font><font color="#007700">;<br /> }<br /> }<br />}<br /><br /></font><font color="#0000BB">$class </font><font color="#007700">= new </font><font color="#0000BB">MyClass</font><font color="#007700">();<br /><br />foreach(</font><font color="#0000BB">$class </font><font color="#007700">as </font><font color="#0000BB">$key </font><font color="#007700">=> </font><font color="#0000BB">$value</font><font color="#007700">) {<br /> print </font><font color="#DD0000">"$key => $value</font><font color="#007700">\n</font><font color="#DD0000">"</font><font color="#007700">;<br />}<br />echo </font><font color="#DD0000">"\n"</font><font color="#007700">;<br /><br /><br /></font><font color="#0000BB">$class</font><font color="#007700">-></font><font color="#0000BB">iterateVisible</font><font color="#007700">();<br /><br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ><P >O exemplo acima irá imprimir:</P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> var1 => value 1<br />var2 => value 2<br />var3 => value 3<br /><br />MyClass::iterateVisible:<br />var1 => value 1<br />var2 => value 2<br />var3 => value 3<br />protected => protected var<br />private => private var</font> </code></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE ><P > Como a saída mostra, o <A HREF="control-structures.foreach.html" >foreach</A > iteragiu por cada uma das variáveis <A HREF="language.oop5.visibility.html" >visíveis</A > que podem ser acessadas. Indo um pouco mais longe, você pode <CODE CLASS="varname" >implementar</CODE > uma das <A HREF="language.oop5.interfaces.html" >interfaces</A > internas do PHP5 chamada <CODE CLASS="varname" >Iterator</CODE >. Isso permite que o objeto decida o que e como o objeto será iterado. </P ><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN5844" ></A ><P ><B >Exemplo 19-22. Iteração de Objeto implmentando Iterator</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br /></font><font color="#007700">class </font><font color="#0000BB">MyIterator implements Iterator<br /></font><font color="#007700">{<br /> </font><font color="#0000BB">private $var </font><font color="#007700">= array();<br /><br /> </font><font color="#0000BB">public </font><font color="#007700">function </font><font color="#0000BB">__construct</font><font color="#007700">(</font><font color="#0000BB">$array</font><font color="#007700">)<br /> {<br /> if (</font><font color="#0000BB">is_array</font><font color="#007700">(</font><font color="#0000BB">$array</font><font color="#007700">) ) {<br /> </font><font color="#0000BB">$this</font><font color="#007700">-></font><font color="#0000BB">var </font><font color="#007700">= </font><font color="#0000BB">$array</font><font color="#007700">;<br /> }<br /> }<br /><br /> </font><font color="#0000BB">public </font><font color="#007700">function </font><font color="#0000BB">rewind</font><font color="#007700">() {<br /> echo </font><font color="#DD0000">"rewinding\n"</font><font color="#007700">;<br /> </font><font color="#0000BB">reset</font><font color="#007700">(</font><font color="#0000BB">$this</font><font color="#007700">-></font><font color="#0000BB">var</font><font color="#007700">);<br /> }<br /><br /> </font><font color="#0000BB">public </font><font color="#007700">function </font><font color="#0000BB">current</font><font color="#007700">() {<br /> </font><font color="#0000BB">$var </font><font color="#007700">= </font><font color="#0000BB">current</font><font color="#007700">(</font><font color="#0000BB">$this</font><font color="#007700">-></font><font color="#0000BB">var</font><font color="#007700">);<br /> echo </font><font color="#DD0000">"current: $var</font><font color="#007700">\n</font><font color="#DD0000">"</font><font color="#007700">;<br /> return </font><font color="#0000BB">$var</font><font color="#007700">;<br /> }<br /><br /> </font><font color="#0000BB">public </font><font color="#007700">function </font><font color="#0000BB">key</font><font color="#007700">() {<br /> </font><font color="#0000BB">$var </font><font color="#007700">= </font><font color="#0000BB">key</font><font color="#007700">(</font><font color="#0000BB">$this</font><font color="#007700">-></font><font color="#0000BB">var</font><font color="#007700">);<br /> echo </font><font color="#DD0000">"key: $var</font><font color="#007700">\n</font><font color="#DD0000">"</font><font color="#007700">;<br /> return </font><font color="#0000BB">$var</font><font color="#007700">;<br /> }<br /><br /> </font><font color="#0000BB">public </font><font color="#007700">function </font><font color="#0000BB">next</font><font color="#007700">() {<br /> </font><font color="#0000BB">$var </font><font color="#007700">= </font><font color="#0000BB">next</font><font color="#007700">(</font><font color="#0000BB">$this</font><font color="#007700">-></font><font color="#0000BB">var</font><font color="#007700">);<br /> echo </font><font color="#DD0000">"next: $var</font><font color="#007700">\n</font><font color="#DD0000">"</font><font color="#007700">;<br /> return </font><font color="#0000BB">$var</font><font color="#007700">;<br /> }<br /><br /> </font><font color="#0000BB">public </font><font color="#007700">function </font><font color="#0000BB">valid</font><font color="#007700">() {<br /> </font><font color="#0000BB">$var </font><font color="#007700">= </font><font color="#0000BB">$this</font><font color="#007700">-></font><font color="#0000BB">current</font><font color="#007700">() !== </font><font color="#0000BB">false</font><font color="#007700">;<br /> echo </font><font color="#DD0000">"valid: </font><font color="#007700">{</font><font color="#DD0000">$var</font><font color="#007700">}\n</font><font color="#DD0000">"</font><font color="#007700">;<br /> return </font><font color="#0000BB">$var</font><font color="#007700">;<br /> }<br />}<br /><br /></font><font color="#0000BB">$values </font><font color="#007700">= array(</font><font color="#0000BB">1</font><font color="#007700">,</font><font color="#0000BB">2</font><font color="#007700">,</font><font color="#0000BB">3</font><font color="#007700">);<br /></font><font color="#0000BB">$it </font><font color="#007700">= new </font><font color="#0000BB">MyIterator</font><font color="#007700">(</font><font color="#0000BB">$values</font><font color="#007700">);<br /><br />foreach (</font><font color="#0000BB">$it </font><font color="#007700">as </font><font color="#0000BB">$a </font><font color="#007700">=> </font><font color="#0000BB">$b</font><font color="#007700">) {<br /> print </font><font color="#DD0000">"$a: $b</font><font color="#007700">\n</font><font color="#DD0000">"</font><font color="#007700">;<br />}<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ><P >O exemplo acima irá imprimir:</P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> rewinding<br />current: 1<br />valid: 1<br />current: 1<br />key: 0<br />0: 1<br />next: 2<br />current: 2<br />valid: 1<br />current: 2<br />key: 1<br />1: 2<br />next: 3<br />current: 3<br />valid: 1<br />current: 3<br />key: 2<br />2: 3<br />next:<br />current:<br />valid:</font> </code></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE ><P > Você também pode definir sua classe para que ela não tenha que definir todas as funções do <CODE CLASS="varname" >Iterator</CODE > simplesmente implementado a interface <CODE CLASS="varname" >IteratorAggregate</CODE > do PHP 5. </P ><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN5852" ></A ><P ><B >Exemplo 19-23. Iteração de Objeto implementado IteratorAggregate</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br /></font><font color="#007700">class </font><font color="#0000BB">MyCollection implements IteratorAggregate </font><font color="#007700">{<br /> </font><font color="#0000BB">private $items </font><font color="#007700">= array();<br /> </font><font color="#0000BB">private $count </font><font color="#007700">= </font><font color="#0000BB">0</font><font color="#007700">;<br /><br /> </font><font color="#FF8000">/* Definião requirida da interface IteratorAggregate */<br /> </font><font color="#0000BB">public </font><font color="#007700">function </font><font color="#0000BB">getIterator</font><font color="#007700">() {<br /> return new </font><font color="#0000BB">MyIterator</font><font color="#007700">(</font><font color="#0000BB">$this</font><font color="#007700">-></font><font color="#0000BB">items</font><font color="#007700">);<br /> }<br /><br /> </font><font color="#0000BB">public </font><font color="#007700">function </font><font color="#0000BB">add</font><font color="#007700">(</font><font color="#0000BB">$value</font><font color="#007700">) {<br /> </font><font color="#0000BB">$this</font><font color="#007700">-></font><font color="#0000BB">items</font><font color="#007700">[</font><font color="#0000BB">$this</font><font color="#007700">-></font><font color="#0000BB">count</font><font color="#007700">++] = </font><font color="#0000BB">$value</font><font color="#007700">;<br /> }<br /><br />}<br /><br /></font><font color="#0000BB">$coll </font><font color="#007700">= new </font><font color="#0000BB">MyCollection</font><font color="#007700">();<br /></font><font color="#0000BB">$coll</font><font color="#007700">-></font><font color="#0000BB">add</font><font color="#007700">(</font><font color="#DD0000">'value 1'</font><font color="#007700">);<br /></font><font color="#0000BB">$coll</font><font color="#007700">-></font><font color="#0000BB">add</font><font color="#007700">(</font><font color="#DD0000">'value 2'</font><font color="#007700">);<br /></font><font color="#0000BB">$coll</font><font color="#007700">-></font><font color="#0000BB">add</font><font color="#007700">(</font><font color="#DD0000">'value 3'</font><font color="#007700">);<br /><br />foreach (</font><font color="#0000BB">$coll </font><font color="#007700">as </font><font color="#0000BB">$key </font><font color="#007700">=> </font><font color="#0000BB">$val</font><font color="#007700">) {<br /> echo </font><font color="#DD0000">"key/value: </font><font color="#007700">[</font><font color="#DD0000">$key -> $val</font><font color="#007700">]\n\n</font><font color="#DD0000">"</font><font color="#007700">;<br />}<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ><P >O exemplo acima irá imprimir:</P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> rewinding<br />current: value 1<br />valid: 1<br />current: value 1<br />key: 0<br />key/value: [0 -> value 1]<br /><br />next: value 2<br />current: value 2<br />valid: 1<br />current: value 2<br />key: 1<br />key/value: [1 -> value 2]<br /><br />next: value 3<br />current: value 3<br />valid: 1<br />current: value 3<br />key: 2<br />key/value: [2 -> value 3]<br /><br />next:<br />current:<br />valid:</font> </code></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE ><DIV CLASS="note" ><BLOCKQUOTE CLASS="note" ><P ><B >Nota: </B > Para mais exemplos de iteração, veja a <A HREF="ref.spl.html" >Extensão SPL</A >. </P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="language.oop5.overloading.html" ACCESSKEY="P" >Anterior</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Principal</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="language.oop5.patterns.html" ACCESSKEY="N" >Próxima</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Sobrecarga</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="language.oop5.html" ACCESSKEY="U" >Acima</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Patterns</TD ></TR ></TABLE ></DIV ></BODY ></HTML >