如何计算数组中的varians数据? [英] How to counting varians data from array?
问题描述
我有一个像这样的数组
$arr = array(1,2,1,3,2,4);
如何计算该数组中的变体数据总数?
How to count total of variant data from that array ?
示例:
$arr = array(1,2,1,3,2,4);
总数= 4
推荐答案
您可以翻转数组,并检查其长度:
You can flip the array, and check its length:
echo count(array_flip($arr));
之所以可行,是因为数组索引必须是唯一的,所以对于原始数组中的每个唯一项,最终都会得到一个元素:
This works because an array index must be unique, so you end up with one element for every unique item in the original array:
http://php.net/manual/en/function.array-flip.php
如果某个值多次出现,则将最新的键用作其值,其他所有键都将丢失.
If a value has several occurrences, the latest key will be used as its value, and all others will be lost.
这是()吗?比 array_unique
快一些,但是除非您将其称为LOT,否则 array_unique
的描述性要强得多,所以可能是更好的选择
This is (was?) somewhat faster than array_unique
, but unless you are calling this a LOT, array_unique
is a lot more descriptive, so probably the better option
这篇关于如何计算数组中的varians数据?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!