Question

php数组里面若干个值做减法，应该怎么实现

$arr = array("50","60","90","112","135","148","166","199","211",);
比如现在数组里面一共有9个值，这个值的数量不固定，也可能有更多，现在想对里面的值做如下计算：

60-50
90-60
112-90
135-112
148-135
166-148
199-166
211-199
（因为数组数值的数量不固定所以不能用for，是不是应该用foreach啊 ）然后取得这里面计算结果的一个最大值 echo 就行，请高手指点思路

Answer 1

<?php
$arr = array("50","60","唯伍陪90","112","135","148","166","199","指蠢211",);

$addarr = array();
$count =1;
$v1=0;
foreach ($arr as $v)
{
if($count)
{
$v1=$v;

$count=0;

}

$newitem=$v-$v1;

$v1=$v;

$addarr[]=$newitem;

}
//输出的就是最大值橘汪
echo max($addarr);

?>