php 二维数组分类

<?php
// 原始二维数组
$data = [
    ['name' => 'Alice', 'age' => 25, 'gender' => 'female'],
    ['name' => 'Bob', 'age' => 30, 'gender' => 'male'],
    ['name' => 'Charlie', 'age' => 25, 'gender' => 'male'],
    ['name' => 'Diana', 'age' => 30, 'gender' => 'female']
];

// 按年龄分类
$groupedByAge = [];
foreach ($data as $person) {
    $age = $person['age'];
    if (!isset($groupedByAge[$age])) {
        $groupedByAge[$age] = [];
    }
    $groupedByAge[$age][] = $person;
}

// 输出分类结果
print_r($groupedByAge);
?>

<?php
function sortByField($a, $b) {
    return strcmp($a['name'], $b['name']);
}

usort($data, 'sortByField');

print_r($data);
?>

<?php
$filteredData = array_filter($data, function($person) {
    return $person['age'] > 25;
});

print_r($filteredData);
?>