Question

我一直用这个来绞尽脑汁。

我有两个数组：

数组1从CSV文件中提取。

Array
(
    [0] => Array
        (
            [uid] => cgajate
            [date] => 20120918
        )

    [1] => Array
        (
            [uid] => badrock5
            [date] => 20120920
        )

    [2] => Array
        (
            [uid] => ricoetc
            [date] => 20120921
        )

    [3] => Array
        (
            [uid] => ricoetc1
            [date] => 20120923
        )

    [4] => Array
        (
            [uid] => darbyfired
            [date] => 20120922
        )

    [5] => Array
        (
            [uid] => sagers.andrew
            [date] => 20120922
        )

    [6] => Array
        (
            [uid] => frankfurt9
            [date] => 20120923
        )

    [7] => Array
        (
            [uid] => beachboys
            [date] => 20120923
        )

    [8] => Array
        (
            [uid] => panterafan
            [date] => 20120923
        )

    [9] => Array
        (
            [uid] => kingsxrules
            [date] => 20120923
        )

    [10] => Array
        (
            [uid] => richard.bitto
            [date] => 20120924
        )

    [11] => Array
        (
            [uid] => christopher.boss
            [date] => 20120925
        )

    [12] => Array
        (
            [uid] => eric.robinson2
            [date] => 20120926
        )

)

数组2从SQL数据库中提取。

Array
(
    [0] => Array
        (
            [uid] => cgajate
            [date] => 20120919
        )

    [1] => Array
        (
            [uid] => ricoetc
            [date] => 20120921
        )

    [2] => Array
        (
            [uid] => ricoetc1
            [date] => 20120922
        )

    [3] => Array
        (
            [uid] => frankfurt9
            [date] => 20120923
        )

    [4] => Array
        (
            [uid] => beachboys
            [date] => 20120923
        )

    [5] => Array
        (
            [uid] => panterafan
            [date] => 20120923
        )

    [6] => Array
        (
            [uid] => kingsxrules
            [date] => 20120923
        )

    [7] => Array
        (
            [uid] => eric.robinson2
            [date] => 20120926
        )

)

我基本上要做的是检查是否有任何UID匹配。如果有匹配，它将检查哪个日期比另一个更新（所以基本上什么日期大于）。然后它会将它们添加到一个数组中，其中UID与两个数组都不匹配。

很抱歉，如果这很难理解。这有点难以解释。

感谢所有的帮助，谢谢大家。

Answer 1

由于PHP数组本身就是哈希映射，您可以遍历一个数组并将每个日期插入到一个新数组中，由UID键入：

$out = array();
foreach ($first_array as $x) {
    $out[$x['uid']] = $x['date'];
}

然后，您可以遍历第二个数组，检查是否有任何UID已作为$out数组中的键存在。如果UID已经存在，那么您可以比较日期并选择您喜欢的任何数据。例如，像：

foreach ($second_array as $y) {
    if (array_key_exists($y['uid'], $out)) {
        if ($out[$y['uid']] < $y['date']) {
            $out[$y['uid']] = $y['date'];
        }
    } else {
        $out[$y['uid']] = $date;
    }
}

然后，将数据压平：

$_out = array();
foreach ($out as $uid => $date) {
    $_out[] = array("uid" => $uid, "date" => $date);
}
$out = $_out;

Answer 2

它有点乱，但它有效。

<?php

$arr1 = array(
    array("uid" => "cgajate", "date" => 20120918),
    array("uid" => "badrock5", "date" => 20120920),
    array("uid" => "ricoetc", "date" => 20120921),
    array("uid" => "ricoetc1", "date" => 20120923),
    array("uid" => "darbyfired", "date" => 20120922),
    array("uid" => "sagers.andrew", "date" => 20120922),
    array("uid" => "frankfurt9", "date" => 20120923),
    array("uid" => "beachboys", "date" => 20120923),
    array("uid" => "panterafan", "date" => 20120923),
    array("uid" => "kingsxrules", "date" => 20120923),
    array("uid" => "richard.bitto", "date" => 20120924),
    array("uid" => "christopher.boss", "date" => 20120925),
    array("uid" => "eric.robinson2", "date" => 20120926));


$arr2 = Array(
    array("uid" => "cgajate", "date" => 20120919),
    array("uid" => "ricoetc", "date" => 20120921),
    array("uid" => "ricoetc1", "date" => 20120922),
    array("uid" => "frankfurt9", "date" => 20120923),
    array("uid" => "beachboys", "date" => 20120923),
    array("uid" => "panterafan", "date" => 20120923),
    array("uid" => "kingsxrules", "date" => 20120923),
    array("uid" => "eric.robinson2", "date" => 20120926));

function flatten ($arr) {
    $new_arr = array ();
    foreach ($arr as $sub_arr) {
        $new_arr[$sub_arr["uid"]] = $sub_arr["date"];
    } 
    return $new_arr;
}


$flat_arr1 = flatten ($arr1);
$flat_arr2 = flatten ($arr2);
$arr3 = array ();

foreach ($flat_arr1 as $key=>$value) {
    if (isset ($flat_arr2[$key])) {
        $value = $flat_arr1[$key] > $flat_arr2[$key] ? $flat_arr1[$key] : $flat_arr2[$key];
    }
    $arr3[$key] = $value;
}

foreach ($flat_arr2 as $key=>$value) {
    if (isset ($flat_arr1[$key])) {
        $value = $flat_arr1[$key] > $flat_arr2[$key] ? $flat_arr1[$key] : $flat_arr2[$key];
    }
    $arr3[$key] = $value;
}

?> 

<pre><?php print_r($flat_arr1); ?></pre>

<pre><?php print_r($flat_arr2); ?></pre>

<pre><?php print_r($arr3); ?></pre>

PHP比较二维数组

2 个答案: