PHP经过长时间的发展,很多用户都很了解PHP了,这里我发表一下个人理解,和大家讨论讨论。我发现很多的PHP程序员,尤其是学习还不是很久的,都不知道PHP的精华所在。Perl当年如何在商界出名?其强大的正则表达式。而PHP呢?他是一门从Unix下发展起来的语言,当然也就继承了Perl的很多特点,同时C的优点都有。
这里,我想来写一篇PHP的变量、数组应用技巧和PHP的正则表达式、PHP模板应用,以后有时间再写PHP与 COM、PHP与XML的完全结合。
1、PHP模板
知道了正则表达式的功能,那么就可以知道模板了。什么是PHP模板?举个例子吧?一般写网页用到了后台程序的时候,都是在网页里面插入程序代码。如PHP。这就是HTML和PHP的混写。这样的优点是读取速度快,缺点是如果大家分工合作做网站,那么非程序员就不会改网了。而用模板,则可以达到分工的最合理化。美工只做页面,程序只写后台,然后再合起来。优秀的Jsp提供了自定义标签的功能很好地完成了模板功能。而主流的PHP如何做到呢?就是利用正则表达式来做到的。可以去网上下载一个PHPLIB,里面的PHP目录下有一个template.inc的源代码文件,那就是用P
2、变量、数组的应用技巧
(1)很多人用得不多的数组函数。foreach、list、each。分别举几个例子,应该就能知道了。例:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 | <ol class = "dp-xml" >
<li class = "alt" ><span><strong><font color= "#006699" ><span class = "tag" ></span><span class = "tag-name" >php</span></font></strong><span> </span></span></li>
<li class = "" >
<span>$</span><span class = "attribute" ><font color= "#ff0000" >data</font></span><span> = </span><span class = "attribute-value" ><font color= "#0000ff" > array </font></span><span>( 'a' =</span><span class = "tag" ><strong><font color= "#006699" >></font></strong></span><span> 'data1' , 'b' =</span><span class = "tag" ><strong><font color= "#006699" >></font></strong></span><span> 'data2' , 'c' =</span><span class = "tag" ><strong><font color= "#006699" >></font></strong></span><span> 'data3' ); </span>
</li>
<li class = "alt" ><span> while (list( $subscript , $value ) = each( $data )) </span></li>
<li class = "" ><span>{ </span></li>
<li class = "alt" >
<span> echo "$</span><span class=" attribute "><font color=" #ff0000 ">subscript</font></span><span> =</span><span class=" tag "><strong><font color=" #006699 ">></font></strong></span><span> $value :: " ; </span>
</li>
<li class = "" >
<span> echo "$</span><span class=" attribute "><font color=" #ff0000 ">subscript</font></span><span> =</span><span class=" tag "><strong><font color=" #006699 ">></font></strong></span><span> $valuen</span><strong><font color=" #006699 "><span class=" tag "><span class=" tag-name ">br</span><span class=" tag ">></span></span></font></strong><span>" ; </span>
</li>
<li class = "alt" ><span>} </span></li>
<li class = "" ><span>reset( $data ); </span></li>
<li class = "alt" >
<span> foreach ( $data as $</span><span class = "attribute" ><font color= "#ff0000" >subscript</font></span><span> =</span><span class = "tag" ><strong><font color= "#006699" >></font></strong></span><span> $value ) </span>
</li>
<li class = "" ><span>{ </span></li>
<li class = "alt" >
<span> echo "$</span><span class=" attribute "><font color=" #ff0000 ">subscript</font></span><span> =</span><span class=" tag "><strong><font color=" #006699 ">></font></strong></span><span> $value :: " ; </span>
</li>
<li class = "" >
<span> echo "$</span><span class=" attribute "><font color=" #ff0000 ">subscript</font></span><span> =</span><span class=" tag "><strong><font color=" #006699 ">></font></strong></span><span> $valuen</span><strong><font color=" #006699 "><span class=" tag "><span class=" tag-name ">br</span><span class=" tag ">></span></span></font></strong><span>" ; </span>
</li>
<li class = "alt" ><span>} </span></li>
</ol>
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(2)函数的变量、变量的变量、变量的“指针”:看下例:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | <ol class = "dp-xml" >
<li class = "alt" ><span><strong><font color= "#006699" ><span class = "tag" ></span><span class = "tag-name" >php</span></font></strong><span> </span></span></li>
<li class = "" ><span>
<li class = "alt" >
<span>$</span><span class = "attribute" ><font color= "#ff0000" > var </font></span><span> = </span><span class = "attribute-value" ><font color= "#0000ff" > "this is a var" </font></span><span>; </span>
</li>
<li class = "" >
<span>$</span><span class = "attribute" ><font color= "#ff0000" >varname</font></span><span> = </span><span class = "attribute-value" ><font color= "#0000ff" > "var" </font></span><span>; </span>
</li>
<li class = "alt" ><span> echo $ $varname ; </span></li>
<li class = "" ><span>
<li class = "alt" ><span> function fun1( $str ) { </span></li>
<li class = "" ><span> echo $str ; </span></li>
<li class = "alt" ><span>} </span></li>
<li class = "" >
<span>$</span><span class = "attribute" ><font color= "#ff0000" >funname</font></span><span> = </span><span class = "attribute-value" ><font color= "#0000ff" > "fun1" </font></span><span>; </span>
</li>
<li class = "alt" ><span> $funname ( "This is a function !" ); </span></li>
<li class = "" >
<span></span><span class = "tag" ><strong><font color= "#006699" >?></font></strong></span><span> </span>
</li>
</ol>
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变量的“指针”。这个指针加上了双引号,表明他不是真正的指针。看看下例:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | <ol class = "dp-xml" >
<li class = "alt" ><span><strong><font color= "#006699" ><span class = "tag" ></span><span class = "tag-name" >php</span></font></strong><span> </span></span></li>
<li class = "" ><span> function ( $a ) { </span></li>
<li class = "alt" ><span> $a ++; </span></li>
<li class = "" ><span>} </span></li>
<li class = "alt" >
<span>$</span><span class = "attribute" ><font color= "#ff0000" >c</font></span><span> = </span><span class = "attribute-value" ><font color= "#0000ff" >0</font></span><span>; </span>
</li>
<li class = "" ><span> function ( $c ); </span></li>
<li class = "alt" ><span> echo $c ;
<li class = "" ><span> function (& $a ) { </span></li>
<li class = "alt" ><span> $a ++; </span></li>
<li class = "" ><span>} </span></li>
<li class = "alt" >
<span>$</span><span class = "attribute" ><font color= "#ff0000" >c</font></span><span> = </span><span class = "attribute-value" ><font color= "#0000ff" >0</font></span><span>; </span>
</li>
<li class = "" ><span> echo $c ;
<li class = "alt" >
<span></span><span class = "tag" ><strong><font color= "#006699" >?></font></strong></span><span> </span>
</li>
</ol>
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之所以称其为“指针”,就是因为他有了和C语言中指针相同的功能。但这又不是真正的指针,只能够是这样的去理解。
3、正则表达式
正则表达式是一个非常大的题目,Perl的正则表达式的强大是闻了名的。而PHP也不弱,他继承了Perl的正则表达式法则,还有自己的一套法则。这里只说PHP自己的正则表达式。正则表达式是最基本的元素。简单地说就是一套规则,用于去判定其它的元素是不是符合自身的规则,或者说是不是有相同的特征描述。正则表达式的开始符:^,结尾符$,这两个符号间的是匹配的元素。如检查一个电话号码是不是打往北京的号,用正则表达式表示就是“^010$”。只要前3位区号是010,就是北京的号,后面的电话号码就不用管了。然后,用正则表达式匹配函数ereg来判断,例:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | <ol class = "dp-xml" >
<li class = "alt" ><span><strong><font color= "#006699" ><span class = "tag" ></span><span class = "tag-name" >php</span></font></strong><span> </span></span></li>
<li class = "" >
<span>$</span><span class = "attribute" ><font color= "#ff0000" >pattern</font></span><span> = </span><span class = "attribute-value" ><font color= "#0000ff" > "^010$" </font></span><span>; </span>
</li>
<li class = "alt" >
<span>$</span><span class = "attribute" ><font color= "#ff0000" >phone</font></span><span> = </span><span class = "attribute-value" ><font color= "#0000ff" > "01080718828" </font></span><span>; </span>
</li>
<li class = "" ><span> if ( ereg ( $pattern , $phone )) </span></li>
<li class = "alt" ><span> echo "打往北京的号" ; </span></li>
<li class = "" ><span> else </span></li>
<li class = "alt" ><span> echo "不是打往北京的号" ; </span></li>
<li class = "" >
<span></span><span class = "tag" ><strong><font color= "#006699" >?></font></strong></span><span> </span>
</li>
</ol>
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这就是正则表达式。北京的电话都是8位数字的,那我要知道这个号码是不是正确了?假如他按了9位号呢?如果判断正误?这就要用到正则表达式的字符簇。那么上例的正则表达式就要这样写:^010[0-9]{8}$,就能同时判断号码是不是符合规则。正则表达式有很多的应用,像LBB、VBB论坛在发贴时的所谓VBB代码LBB代码的解析,都是用正则表达式完成的。