PHP 獲取數組任意下標key的上一個prev和下一個next下標值
$value){
$steps->add($key);
}
$steps->setCurrent(3);//參數為key值
echo '上一個下標：'.$steps->getPrev()."
";
echo '指定的下標：'.$steps->getCurrent()."
";
echo '下一個下標：'.$steps->getNext()."
";
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);
}
}
上一個下標：2 指定的下標：3 下一個下標：4
