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<p>當我們例項化一個php類的時候，要怎麼傳遞引數呢？這取決於該類的構造方法。</p>
<p>例：</p>
<p>person.class.php</p>
<p></p>
<pre onclick="hljs.copyCode(event)"><code class="language-php hljs"><ol class="hljs-ln" style="width:1001px"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">&lt;?php</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">    <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">person</span></span>{</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">        <span class="hljs-keyword">var</span> $name;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">        <span class="hljs-keyword">var</span> $color;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">        <span class="hljs-keyword">var</span> $sex;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">        <span class="hljs-keyword">var</span> $age;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">        <span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">__construct</span><span class="hljs-params">($name,$age=<span class="hljs-string">''</span>,$sex=<span class="hljs-string">'boy'</span>)</span></span>{</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="8"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">            <span class="hljs-keyword">$this</span>-&gt;name = $name;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="9"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">            <span class="hljs-keyword">$this</span>-&gt;age = $age;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="10"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">            <span class="hljs-keyword">$this</span>-&gt;sex = $sex;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="11"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">            <span class="hljs-keyword">$this</span>-&gt;color = <span class="hljs-string">'yello'</span>;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="12"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">        }</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="13"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">        <span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">eat</span><span class="hljs-params">()</span></span>{</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="14"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">            <span class="hljs-keyword">echo</span> <span class="hljs-keyword">$this</span>-&gt;name.<span class="hljs-string">'要吃飯'</span>;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="15"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">        }</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="16"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">        <span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">xinxi</span><span class="hljs-params">()</span></span>{</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="17"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">            <span class="hljs-keyword">echo</span> <span class="hljs-keyword">$this</span>-&gt;name.<span class="hljs-string">' is '</span>.<span class="hljs-keyword">$this</span>-&gt;sex.<span class="hljs-string">' and age is '</span>.<span class="hljs-keyword">$this</span>-&gt;age.<span class="hljs-string">' fuse is '</span>.<span class="hljs-keyword">$this</span>-&gt;color;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="18"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">        }</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="19"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">        <span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">zuoyong</span><span class="hljs-params">()</span></span>{</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="20"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">            <span class="hljs-comment">//類似於這樣的內部呼叫，相當於把eat()的程式碼引入到zuoyong()裡面，而不是跳轉到eat()裡面繼續執行</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="21"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">            <span class="hljs-comment">//如果是http://localhost/zuoyong?food=xigua這樣的url來呼叫zuoyong()</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="22"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">            <span class="hljs-comment">//那麼eat()中可直接通過$_GET['food']獲取url引數，因為全域性變數可在函式內部使用</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="23"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">            <span class="hljs-keyword">$this</span>-&gt;eat();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="24"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">        }        </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="25"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">    }</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="26"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">?&gt;</span></div></div></li></ol></code><div class="hljs-button" data-title="複製"></div></pre>son.php
<p></p>
<pre onclick="hljs.copyCode(event)"><code class="language-html hljs xml"><ol class="hljs-ln"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="php"><span class="hljs-meta">&lt;?php</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">    <span class="hljs-keyword">include</span>(<span class="hljs-string">'person.class.php'</span>);</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">    $son = <span class="hljs-keyword">new</span> person(<span class="hljs-string">'cuihua'</span>,<span class="hljs-number">25</span>,<span class="hljs-string">'girl'</span>);<span class="hljs-comment">//此處的引數傳遞要和類的構造方法裡面的引數順序對應</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">    <span class="hljs-comment">//$son-&gt;xinxi();//cuihua is girl and age is 25 fuse is yello</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">    $son-&gt;name = <span class="hljs-string">'田妞'</span>;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">    $son-&gt;eat();<span class="hljs-comment">//田妞要吃飯</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">?&gt;</span></div></div></li></ol></code><div class="hljs-button" data-title="複製"></div></pre><br><p>注：php類的屬性（$name、$age等）可以在該類的全域性範圍內使用，可以把類的屬性視為“該類的”全域性變數。但是當外部程式重新呼叫這個類中的方法時，該類會重新被例項化，也就是說要再次執行構造方法，那麼上一次給$name等屬性賦的值就會被清空，所以$name等屬性的值不會像常量或是session中的值那樣一直保持下去。</p>
<p><br></p>
<p>son2.php</p>
<p></p>
<pre onclick="hljs.copyCode(event)"><code class="language-php hljs"><ol class="hljs-ln"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">&lt;?php</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">    <span class="hljs-keyword">include</span>(<span class="hljs-string">'person.class.php'</span>);</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">    $son = <span class="hljs-keyword">new</span> person(<span class="hljs-string">'cuihua'</span>,<span class="hljs-number">25</span>,<span class="hljs-string">'girl'</span>);</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">    $son2 = $son;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">    $son2-&gt;name = <span class="hljs-string">'田妞'</span>;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">    $son-&gt;eat();<span class="hljs-comment">//田妞要吃飯</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">?&gt;</span></div></div></li></ol></code><div class="hljs-button" data-title="複製"></div></pre>當我把$son物件賦予$sin2之後，改變了$son2的name引數，此時發現$son的name引數也響應的跟著改變，由此可見：在php5中，把物件賦值給變數，是按引用傳遞物件，而不是進行值傳遞，此時並不會建立$son的副本。傳遞物件到函式，或從方法返回物件，是引用傳遞還是值傳遞，待驗證。<br><p></p>
<p>****************************************************************************************</p>
<p>可以通過var_dump()列印物件，不過只能列印物件的屬性，它的方法不能打印出來，要想獲取物件的方法列表，可以用get_class_methods函式。</p>
<p></p><pre onclick="hljs.copyCode(event)"><code class="language-php hljs"><ol class="hljs-ln"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">&lt;?php</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">$son = <span class="hljs-keyword">new</span> person(<span class="hljs-string">'cuihua'</span>,<span class="hljs-number">25</span>,<span class="hljs-string">'girl'</span>);</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">var_dump($son);</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"><span class="hljs-comment">/*</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">object(person)[1]</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">  public 'name' =&gt; string 'cuihua' (length=6)</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">  public 'color' =&gt; string 'yello' (length=5)</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="8"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">  public 'sex' =&gt; string 'girl' (length=4)</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="9"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">  public 'age' =&gt; int 25</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="10"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">*/</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="11"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="12"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">$mon = get_class_methods($son);</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="13"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">var_dump($mon);</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="14"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment"><span class="hljs-comment">/*</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="15"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">array (size=4)</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="16"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">  0 =&gt; string '__construct' (length=11)</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="17"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">  1 =&gt; string 'eat' (length=3)</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="18"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">  2 =&gt; string 'xinxi' (length=5)</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="19"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">  3 =&gt; string 'zuoyong' (length=7)</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="20"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">*/</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="21"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">?&gt;</span></div></div></li></ol></code><div class="hljs-button" data-title="複製"></div></pre><br><br><p></p>
            </div>
                </div>