玩转PHP数值函数
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。
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>
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>
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>
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>
(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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