自定義排序函數(shù)返回false或負(fù)數(shù)意味著第一個參數(shù)應(yīng)該排在第二個參數(shù)的前面, 正數(shù)或true反之, 0相等
usort不保存鍵名
uasort 鍵名會保存下來
uksort 排序是對鍵名進(jìn)行的

    <meta charset="utf-8">
    <title>Sorting Multidimensional Arrays</title>


<?php $a = [
    [
        'key1' => 940,
        'key2' => 'blah',
    ],
    [
        'key1' => 23,
        'key2' => 'this',
    ],
    [
        'key1' => 894,
        'key2' => 'that',
    ],
];

var_dump($a);
// 比較的規(guī)則第一個小于第二個返回負(fù)數(shù)或false, 相當(dāng)于第一個的值減去第二個, 如果前小后大則為負(fù), 前大后小則為正, 兩個一樣, 則為0

//按第一個數(shù)組key1的數(shù)字從小到大排序
function asc_number_sort($x, $y) {
    echo "iteration x1 = ".$x['key1'].' y = '.$y['key1'];
    if ($x['key1'] > $y['key1']) {
        return true; // true或正數(shù)表示第二個參數(shù)應(yīng)該排在前面, 小的在前
    } elseif ($x['key1']  ["name" => "Name", "grade" => xx.x];

    $students = [
        256 => ['name' => 'Jon', 'grade' => '98.5'],
        2 => ['name' => 'Vance', 'grade' => '85.1'],
        9 => ['name' => 'Stephen', 'grade' => '94.0'],
        364 => ['name' => 'Steve', 'grade' => '85.1'],
        68 => ['name' => 'Rob', 'grade' => '74.6'],
    ];

    function name_sort($x, $y) {
        return strcasecmp($x['name'], $y['name']);
    }

    function grade_sort($x, $y) {
        return $x['grade'] 

    <meta charset="utf-8">
    <title>Sorting Multidimensional Arrays</title>


<?php $db = mysqli_connect('192.168.31.172', 'root', 'root', 'phpadvanced');
mysqli_query($db, "set names utf8");

if(!empty($_POST['task'])) {
    $parent_id = 0;
    if(isset($_POST['parent_id']) && filter_var($_POST['parent_id'], FILTER_VALIDATE_INT, ['min_range' => 1])) {
        $parent_id = $_POST['parent_id'];
    }

    $task = mysqli_real_escape_string($db, strip_tags($_POST['task']));

    $q = "INSERT INTO tasks (parent_id, task) VALUES ($parent_id, '$task')";
    echo $q;
    $r = mysqli_query($db, $q);

    if(mysqli_affected_rows($db) == 1) {
        echo '<p>任務(wù)添加成功</p>';
    } else {
        echo '<p>任務(wù)添加失敗</p>';
    }
}
?>
    

添加一個任務(wù)

任務(wù):

上級任務(wù): 無上級 $task"; $tasks[] = ['task_id' => $task_id, 'parent_id' => $parent_id, 'task' => $task]; } ?>

$y['parent_id']); } usort($tasks, 'parent_sort'); echo '

當(dāng)前的任務(wù)列表

'; foreach ($tasks as $task) { echo "
• {$task['task']}
\n"; } echo '

'; ?>

CREATE TABLE tasks (
  task_id INT UNSIGNED NOT NULL AUTO_INCREMENT,
  parent_id INT UNSIGNED NOT NULL DEFAULT 0,
  task VARCHAR(100) NOT NULL,
  date_added TIMESTAMP NOT NULL,
  date_completed TIMESTAMP,
  PRIMARY KEY (task_id),
  INDEX parent (parent_id),
  INDEX added (date_added),
  INDEX completed (date_completed)
);

以上就介紹了php多維數(shù)組排序以及實際工作中的應(yīng)用，包括了方面的內(nèi)容，希望對PHP教程有興趣的朋友有所幫助。