php入门学习知识点七PHP函数的基本应用_PHP教程

<br><!--?php <BR-->/* <br>* 简单的函数 <br>*/ <br>function fontBold($con){ <br>return "<b>$con</b>"; <br>} <br>$str="简单的函数测试！"; <br>echo "普通文本：$str<br>"; <br>echo "加粗文本:".fontBold($str).""; <br>/* <br>* 带可选参数的函数 <br>*/ <br>function fontColor($con,$color="bule"){ <br>return "<font color="\"$color\"">$con</font>"; <br>} <br>$str="颜色测试"; <br>echo $str; <br>echo fontColor($str."这是不带颜色参数的（默认为蓝色）！"); <br>echo fontColor($str,"red"."这是带颜色参数的(默认为红色！)"); <br>/* <br>* 递归函数 <br>*/ <br>function chckint($Num){ <br>if($Num>1){ <br>return chckint($Num-1); <br>}else if($Num<0){ <br>return chckint(($Num*-1)-1); <br>}else{ <br>if($Num>0 && $Num<1){ <br>return false; <br>}else if($Num){ <br>return true; <br>} <br>} <br>} <br>$Num=3; <br>if(chckint($Num)){ <br>echo $Num."是整数！"; <br>}else{ <br>echo $Num."不是整数"; <br>} <br>/* <br>*动态调用函数 <br>*/ <br>function write($con){ <br>echo "$con"; <br>} <br>function writeBold($con){ <br>echo "<b>$con</b>"; <br>} <br>$myFupnction="write"; <br>$myFupnction("这是动态调用函数不加粗的例子！"); <br>$myFupnction="writeBold"; <br>$myFupnction("这是动态调用加粗的例子！") <br>?> <br>
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<p align="left"><span id="url" itemprop="url">http://www.bkjia.com/PHPjc/323821.html</span><span id="indexUrl" itemprop="indexUrl">www.bkjia.com</span><span id="isOriginal" itemprop="isOriginal">true</span><span id="isBasedOnUrl" itemprop="isBasedOnUrl">http://www.bkjia.com/PHPjc/323821.html</span><span id="genre" itemprop="genre">TechArticle</span><span id="description" itemprop="description"> 代码如下:</span></p><pre class="brush:php;toolbar:false layui-box layui-code-view layui-code-notepad"><ol class="layui-code-ol"><li>?php /* * 简单的函数 */ function fontBold($con){ return "B$con/B"; } $str="简单的函数测试！"; echo "普通文本：$strbr"; echo "加粗文本...<p></p></li><li>                    </li></ol></pre>