配列フィルタいろいろ

array_filter_and_merge.php

<?php
namespace Acme;

// フィルタに通れば上書き、なければそのまま
$data1 = array(
    'name ' => '',
    'age'   => '20',
    'notes' => 'HOGE',
);
$data2 = array(
    'name'  => 'TEST',
    'age'   => null,
    'notes' => 'FUGA',
);

echo '<pre>';
printf('$data1 = %s', print_r($data1, true));
echo '</pre>';

echo '<pre>';
printf('$data2 = %s', print_r($data2, true));
echo '</pre>';

$filter = function($value) {
    return (isset($value) && strlen($value) >= 1);
};

$merged_data = array_replace(
    array_filter($data1, $filter),
    array_filter($data2, $filter));
echo '<pre>';
printf('$merged_data = %s', print_r($merged_data, true));
echo '</pre>';

array_intersect_ukey.php

<?php
namespace Acme;

// array_intersect_ukey()を使って配列の要素をキーでフィルタ
// via http://blog.sarabande.jp/post/24178664526
$accept_keys = array(
    'name','age',
);

$data = array(
    'invalid' => 'HOGE',
    'name'    => 'test',
    'unko'    => 'UNKO',
    'age'     => '20',
);

echo '<pre>';
printf('$data = %s', print_r($data, true));
echo '</pre>';

// One-linerで書くなら
$filtered_data = array_intersect_ukey($data, $data,
    function($key1, $key2) use ($accept_keys) {
        return in_array($key1, $accept_keys) ? 0 : 1;
    }
);
echo '<pre>';
printf('$filtered_data = %s', print_r($filtered_data, true));
echo '</pre>';


// フィルタを外部に定義するなら
$filter = function($key) use ($accept_keys) {
    return in_array($key, $accept_keys);
};

$filtered_data = array_intersect_ukey($data, $data,
    function($key1, $key2) use ($filter) {
        return $filter($key1) ? 0 : 1;
    }
);
echo '<pre>';
printf('$filtered_data = %s', print_r($filtered_data, true));
echo '</pre>';