实际上一个循环就足够了：

<?php
$order = [15, 17, 3];
$input = [
  [
    'id'  => 1,
    'name' => 'Test 1',
    'classId' => 3,
  ],
  [
    'id'  => 1,
    'name' => 'Test 1',
    'classId' => 15,
  ],
  [
    'id'  => 1,
    'name' => 'Test 1',
    'classId' => 17,
  ],
];
$output = [];
array_walk($input, function($entry) use ($order, &$output) {
  $output[array_search($entry['classId'], $order)] = $entry;
});
ksort($output);
print_r($output);

如果你认为array_search(...)也是一个“循环”（尽管它内部的工作方式不同），那么这将是一个产生相同输出的替代方案：

<?php
$order = array_flip([15, 17, 3]);
$input = array_values([
  [
    'id'  => 1,
    'name' => 'Test 1',
    'classId' => 3,
  ],
  [
    'id'  => 1,
    'name' => 'Test 1',
    'classId' => 15,
  ],
  [
    'id'  => 1,
    'name' => 'Test 1',
    'classId' => 17,
  ],
]);
$output = [];
array_walk($input, function($entry, $index) use ($order, &$output) {
  $output[$order[$entry['classId']]] = $entry;
});
ksort($output);
print_r($output);

这两种方法的输出为：

Array
(
    [0] => Array
        (
            [id] => 1
            [name] => Test 1
            [classId] => 15
        )
    [1] => Array
        (
            [id] => 1
            [name] => Test 1
            [classId] => 17
        )
    [2] => Array
        (
            [id] => 1
            [name] => Test 1
            [classId] => 3
        )
)

您可以使用usort和一个匿名比较函数（从$classIds检索目标索引）直接对数组进行就地排序。
给定

<?php
$arr = array(
   0 => array(
         'id'  => 1,
         'name' => 'Test 1',
         'classId' => 3
       ),
  1 => array(
         'id'  => 1,
         'name' => 'Test 1',
         'classId' => 15
       ),
  2 => array(
         'id'  => 1,
         'name' => 'Test 1',
         'classId' => 17
       ),
);
$classIds = [15, 17, 3];

你可以用

// Create assoc array mapping classIds to their desired sorted position.
$classIdsOrder = array_combine($classIds, range(0, count($classIds)-1));

// Sort $arr according to the 'classId' order described by $classIdsOrder
usort($arr, function ($left, $right) use ($classIdsOrder) {
    return $classIdsOrder[$left['classId']] <=> $classIdsOrder[$right['classId']];
});

print_r($arr);

其输出

Array
(
    [0] => Array
        (
            [id] => 1
            [name] => Test 1
            [classId] => 15
        )

    [1] => Array
        (
            [id] => 1
            [name] => Test 1
            [classId] => 17
        )

    [2] => Array
        (
            [id] => 1
            [name] => Test 1
            [classId] => 3
        )

)

Try it online!