在php中仅为数组中的最大值优化代码[关闭]

Question

hi there I designed a blog page....per page 10 artilcs!

I want return biggest time (stamptime) for each 10 articls (like publish up time,publish down time,created,modifed time) to create meta tag.

so I have a list of 10 artiles (each article is an array with all parameters like date,content,title,...) that I saved them in $list array.

like this:

$list =  array ( array('id' => '1', 'modifed ' => '123123123' ...

I want return biggest value...the articls are mixed.

I use this code:

   $data['created'] = array_reduce($list, function ($a, $b) {
        return @$a['created'] > $b['created'] ? $a : $b ;

    $data['modified'] = array_reduce($list, function ($a, $b) {
        return @$a['modified'] > $b['modified'] ? $a : $b ;

    $data['publish_up'] = array_reduce($list, function ($a, $b) {
        return @$a['publish_up'] > $b['publish_up'] ? $a : $b ;

    $data['publish_down'] = array_reduce($list, function ($a, $b) {
        return @$a['publish_down'] > $b['publish_down'] ? $a : $b ; 

My only worry is it maybe has a bad effect in my loading page.

do you think this code is Optimized?

Answer 1

Here's my solution. But as Sven said, you need to be more specific.

//fake data
$data = array(
    array('id' => 1, 'upd' => 111, 'created' => 333),
    array('id' => 2, 'upd' => 1203, 'created' => 43),
    array('id' => 3, 'upd' => 144, 'created' => 533),
);

// here, I'm first computing the max of each column
// I place the results in an array and returns ultimately the max
echo max(
    array(
        max(array_column($data, 'upd')),
        max(array_column($data, 'created'))
    )
);
// here, it returns 1203, as there is an element "upd" with value 1203

If you do not have php 5.5, you have the following options:

1. use a php implementation that matches the behaviour of php 5.5 : https://github.com/ramsey/array_column/blob/master/src/array_column.php

2. upgrade to php 5.5 ;)

3. implements the function with map

The option 3 leads to the following code:

echo max(
    array(
        max(array_map(function($arr){return $arr['upd'];}, $data)),
        max(array_map(function($arr){return $arr['created'];}, $data)),
    )
);