<?php
printf('b: %b <br>c: %c <br>d: %d <bf>f: %f', 80,80, 80, 80);
echo '<br />';
printf('%0.2f <br>%+d <br>%0.2f <br>', 8, 8, 1235.456);
printf('the cost of %d %s at $%0.2f each is $%0.2f.', 4, 'brooms', 8.50, (4*8.50));
echo '<br>';
$tax = 30;
printf('The tax rate is %0.2f%%', $tax);
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Sorting Multidimensional Arrays</title>
</head>
<body>
<?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'];
}
$q = sprintf("INSERT INTO tasks (parent_id, task) VALUES (%d, '%s')", $parent_id, mysqli_real_escape_string($db, strip_tags($_POST['task'])));
$r = mysqli_query($db, $q);
if(mysqli_affected_rows($db) == 1) {
echo '<p>任务添加成功</p>';
} else {
echo '<p>任务添加失败</p>';
}
}
?>
<form action="add_task.php" method="post">
<fieldset>
<legend>添加一个任务</legend>
<p>任务: <input name="task" type="text" size="60" maxlength="100" required> </p>
<p>上级任务: <select name="parent_id">
<option value="0">无上级</option>
<?php
$q = 'SELECT task_id, parent_id, task FROM tasks WHERE date_completed="0000-00-00 00:00:00" ORDER BY date_added ASC';
$r = mysqli_query($db, $q);
$tasks = [];
while(list($task_id, $parent_id, $task) = mysqli_fetch_array($r, MYSQLI_NUM)) {
echo "<option value=\"$task_id\">$task</option>";
$tasks[] = ['task_id' => $task_id, 'parent_id' => $parent_id, 'task' => $task];
}
?>
</select></p>
<input name="submit" type="submit" value="添加这个任务" />
</fieldset>
</form>
<?php
// 对任务的父id进行排序
function parent_sort($x, $y) {
return ($x['parent_id'] > $y['parent_id']);
}
usort($tasks, 'parent_sort');
echo '<h2>当前的任务列表</h2><ul>';
foreach ($tasks as $task) {
echo "<li>{$task['task']}</li>\n";
}
echo '</ul>';
?>
</body>
</html>
