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玩转PHP数值函数

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Release: 2016-06-13 11:04:26
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PHP有很多值得学习的地方,这里我们主要介绍PHP数组函数,下面我们先简单的总结一下PHP吧。对于普通电脑爱好者来说,PHP或许是一个陌生的名字。比较关注网络的朋友,特别是关注网站建设技术的朋友,可能听说过PHP。PHP是一种为动态创建HTML内容而设计的简单但功能强大的编程语言。

PHP本身是一种简单而强大的语言。PHP语言拥有核心特性如强大的字符串和数组处理能力,同时极大的改进了对面向对象编程的支持(PHP5以上版本)。通过使用标准的和可选的扩展模块,PHP应用程序可以连接MySQL或Oracle等十几种数据库、绘图、创建PDF文件和创建解析XML文件。你也可以使用C语言来写自己的PHP扩展模块。例如,在已存在的代码库中提供一个PHP的接口函数。你也可以在Windows下运行PHP,使用COM控制其它诸如Word和Excel的Windows应用程序,或者使用ODBC来连接数据库。以上就简短的对PHP的介绍,下面我们来看看PHP数组函数的相关知识。

1.返回当前数组值的键的函数key(),结束时返回false

<ol class="dp-xml">
<li class="alt"><span><span>$</span><span class="attribute"><font color="#ff0000">a</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">array</font></span><span>("tom"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>"21","jim"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>"22","andy"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>"25");  </span></span></li>
<li class=""><span>//配置key函数循环读取$a的键并赋值$key,直到读取完毕  </span></li>
<li class="alt">
<span>while($</span><span class="attribute"><font color="#ff0000">key</font></span><span class="attribute-value"><font color="#0000ff">key</font></span><span>=key($a)){  </span>
</li>
<li class=""><span>echo $key;  </span></li>
<li class="alt"><span>//next负责将数组指针移向下一个  </span></li>
<li class=""><span>next($a);  </span></li>
<li class="alt"><span>} </span></li>
</ol>
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2.获取当前指针的PHP数值函数current,结束时返回false

<ol class="dp-xml">
<li class="alt"><span><span>$</span><span class="attribute"><font color="#ff0000">a</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">array</font></span><span>("tom"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>"21","jim"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>"22","andy"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>"25");  </span></span></li>
<li class=""><span>//配置key函数循环读取$a的数组值并赋值$key,直到读取完毕  </span></li>
<li class="alt">
<span>while($</span><span class="attribute"><font color="#ff0000">key</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">current</font></span><span>($a)){  </span>
</li>
<li class=""><span>echo $key;  </span></li>
<li class="alt"><span>next($a);  </span></li>
<li class=""><span>} </span></li>
</ol>
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3.以上两例的合并版each() 返回的是数组,可以借助list读取。

并且可以省略next,因为他自动跳转了

<ol class="dp-xml">
<li class="alt"><span><span>$</span><span class="attribute"><font color="#ff0000">a</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">array</font></span><span>("tom"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>"21","jim"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>"22","andy"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>"25");  </span></span></li>
<li class=""><span>//配置循环读取$a的数组值与键并分别赋值,直到读取完毕  </span></li>
<li class="alt"><span>while(list($key, $val)=each($a)){  </span></li>
<li class="">
<span>echo $key,$val,"</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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4.特别记一下,移动指针的函数

(1)next语句,顾名思义移动到下一个的意思

<ol class="dp-xml">
<li class="alt"><span><span>$</span><span class="attribute">a</span><span>=</span><span class="attribute-value">array</span><span>("tom","jim","andy");  </span></span></li>
<li class=""><span>echo next($a);//输出jim  </span></li>
<li class="alt"><span>echo next($a);//输出andy </span></li>
</ol>
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(2)prev语句,前移指针的语句。同上就不举例了

(3)reset语句,回到第一个位置,同上也不举例的

(4)end语句,到最后一个,就不举例!!


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