PHP array_filter带参数 [英] PHP array_filter with arguments

问题描述

我有以下的code：

function lower_than_10($i) {
    return ($i < 10);
}

这是我可以用它来过滤数组是这样的：

that I can use to filter an array like this:

$arr = array(7, 8, 9, 10, 11, 12, 13);
$new_arr = array_filter($arr, 'lower_than_10');

我如何添加参数lower_than_10以便它也接受对证多少？就像，如果我有这样的：

How can I add arguments to lower_than_10 so that it also accepts the number to check against? Like, if I have this:

function lower_than($i, $num) {
    return ($i < $num);
}

如何从调用array_filter经过10至$ NUM或什么号码？

how to call it from array_filter passing 10 to $num or whatever number?

推荐答案

作为替代@查尔斯的<一个href=\"http://stackoverflow.com/questions/5482989/php-array-filter-with-arguments/5483102#5483102\">solution使用闭包，实际上你可以发现在评论为例文档页面上。 的想法是，你创建所需的状态（ $ NUM ）和回调方法（以 $ I 作为参数）：

As an alternative to @Charles's solution using closures, you can actually find an example in the comments on the documentation page. The idea is that you create an object with the desired state ($num) and the callback method (taking $i as an argument):

class LowerThanFilter {
        private $num;

        function __construct($num) {
                $this->num = $num;
        }

        function isLower($i) {
                return $i < $this->num;
        }
}

使用（演示）：

$arr = array(7, 8, 9, 10, 11, 12, 13);
$matches = array_filter($arr, array(new LowerThanFilter(12), 'isLower'));
print_r($matches);

---

一点题外话，你现在可以替换 LowerThanFilter 有一个更通用 NumericComparisonFilter 像<$ C $方法C> islower判断， isGreater ，的isEqual 等只是一个想法＆MDASH;和演示 ...

---

As a sidenote, you can now replace LowerThanFilter with a more generic NumericComparisonFilter with methods like isLower, isGreater, isEqual etc. Just a thought — and a demo...

这篇关于PHP array_filter带参数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！