PHP 获取数组任意下标key的上一个prev和下一个next下标值
<?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);
}
}
打印结果：
上一个下标：2 指定的下标：3 下一个下标：4