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经验之谈PHP数组函数总结_PHP教程

时间:2021-07-01 10:21:17 帮助过:14人阅读

这几天在网上看了很多有关PHP数组函数的相关知识,觉得孔老夫子的“温故而知新”果然不假,这里是我总结的一些经验,希望对大家有帮助。

PHP中的数组实际上是一个有序图,图是一种把values映射到keys的类型。此类型在很多方面做了优化,因此你可以把它当成真正的数组来使用,或列表(矢量),散列表(是图的一种实现),字典,集合,栈,队列以及更多可能性。因为可以用另一个PHP数组作为值,也可以很容易地模拟树。解释这些结构超出了本手册的范围,但对于每种结构你至少会发现一个例子。要得到这些结构的更多信息,我们建议你参考有关此广阔主题的外部著作,以下特记下我的一些PHP数组函数体会:

1.将一个1维数组分割成2维数组array_chunk()

  1. <ol class="dp-xml"><li class="alt"><span><span>$</span><span class="attribute"><font color="#ff0000">input_array</font></span><span>=array('a','b','c','d','e'); </span></span></li><li class=""><span>print_r(array_chunk($input_array,2)); </span></li></ol>

2.比较2个数组,array_diff_assoc()或者array_diff(),如果返回值为空,表示两个数组相同,否则就不同。

3.用一个函数来过滤数组中的数值array_filter()

  1. <ol class="dp-xml"><li class="alt"><span><span>functionodd($var){ </span></span></li><li class=""><span>return($var%</span><span class="attribute"><font color="#ff0000">2</font></span><span>==1); </span></li><li class="alt"><span>} </span></li><li class=""><span>functioneven($var){ </span></li><li class="alt"><span>return($var%</span><span class="attribute"><font color="#ff0000">2</font></span><span>==0); </span></li><li class=""><span>} </span></li><li class="alt"><span>$</span><span class="attribute-value"><font color="#0000ff">array</font></span><span class="attribute"><font color="#ff0000">array1</font></span><span>=array("a"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>1,"b"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>2,"c"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>3,"d"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>4,"e"=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>5); </span></li><li class=""><span>$</span><span class="attribute-value"><font color="#0000ff">array</font></span><span class="attribute"><font color="#ff0000">array2</font></span><span>=array(6,7,8,9,10,11,12); </span></li><li class="alt"><span>echo"Odd:n"; </span></li><li class=""><span>print_r(array_filter($array1,"odd")); </span></li><li class="alt"><span>echo"Even:n"; </span></li><li class=""><span>print_r(array_filter($array2,"even")); </span></li><li class="alt"><span></span><span class="tag"><strong><font color="#006699">?></font></strong></span><span> </span></li></ol>

4.array_map()将回调函数作用到给定数组的单元上,它的参数可以是一个数组,也可以是多个数组,回调函数的参数必须要和调用它的参数相同。

  1. <ol class="dp-xml"><li class="alt"><span><span>//单个参数的例子,将数组中的每个值,乘以它的3次方 </span></span></li><li class=""><span>functioncube($n){ </span></li><li class="alt"><span>return$n*$n*$n; </span></li><li class=""><span>} </span></li><li class="alt"><span> </span></li><li class=""><span>$</span><span class="attribute">a</span><span>=</span><span class="attribute-value">array</span><span>(1,2,3,4,5); </span></li><li class="alt"><span>$</span><span class="attribute">b</span><span>=</span><span class="attribute-value">array_map</span><span>("cube",$a); </span></li><li class=""><span>print_r($b); </span></li><li class="alt"><span></span><span class="tag">?></span><span> </span></li><li class=""><span> </span></li><li class="alt"><span>//多个数组参数的例子 </span></li><li class=""><span>functionshow_Spanish($n,$m){ </span></li><li class="alt"><span>return"Thenumber$niscalled$minSpanish"; </span></li><li class=""><span>} </span></li><li class="alt"><span> </span></li><li class=""><span>functionmap_Spanish($n,$m){ </span></li><li class="alt"><span>returnarray($</span><span class="attribute">n</span><span>=</span><span class="tag">></span><span>$m); </span></li><li class=""><span>} </span></li><li class="alt"><span> </span></li><li class=""><span>$</span><span class="attribute">a</span><span>=</span><span class="attribute-value">array</span><span>(1,2,3,4,5); </span></li><li class="alt"><span>$</span><span class="attribute">b</span><span>=</span><span class="attribute-value">array</span><span>("uno","dos","tres","cuatro","cinco"); </span></li><li class=""><span> </span></li><li class="alt"><span>$</span><span class="attribute">c</span><span>=</span><span class="attribute-value">array_map</span><span>("show_Spanish",$a,$b); </span></li><li class=""><span>print_r($c); </span></li><li class="alt"><span>$</span><span class="attribute">d</span><span>=</span><span class="attribute-value">array_map</span><span>("map_Spanish",$a,$b); </span></li><li class=""><span>print_r($d); </span></li><li class="alt"><span></span><span class="tag">?></span><span> </span></li><li class=""><span>//</span></li></ol>
输出结果
  • //printoutof$c
  • Array
  • (
  • [0]=>Thenumber1iscalledunoinSpanish
  • [1]=>Thenumber2iscalleddosinSpanish
  • [2]=>Thenumber3iscalledtresinSpanish
  • [3]=>Thenumber4iscalledcuatroinSpanish
  • [4]=>Thenumber5iscalledcincoinSpanish
  • )
  • 以上就是有关PHP数组函数的相关总结,大家要熟记啊。


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