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PHP gets the previous prev and next subscript value of any subscript key in the array
<?php $xoops[1] = '小'; $xoops[2] = '孩'; $xoops[3] = '子'; $xoops[4] = '气'; $steps = new Steps(); foreach($xoops as $key=>$value){ $steps->add($key); } $steps->setCurrent(3);//参数为key值 echo '上一个下标:'.$steps->getPrev()."<br />"; echo '指定的下标:'.$steps->getCurrent()."<br />"; echo '下一个下标:'.$steps->getNext()."<br />"; class Steps { private $all; private $count; private $curr; function __construct() { $this->count = 0; } function add($step) { $this->count++; $this->all[$this->count] = $step; } function setCurrent($step) { reset($this->all); for ($i = 1; $i <= $this->count; $i++) { if ($this->all[$i] == $step) break; next($this->all); } $this->curr = current($this->all); } function getCurrent() { return $this->curr; } function getNext() { self::setCurrent($this->curr); return next($this->all); } function getPrev() { self::setCurrent($this->curr); return prev($this->all); } }
上一个下标:2 指定的下标:3 下一个下标:4