PHP 迭代键和值，并根据数组键整数差拆分为子数组

这里

令人头疼，我厌倦了迭代键和值并操纵指针来比较数组键中整数之间的差异。我正在尝试根据数组键大于 1 的减法来拆分和排列这个数组，我很早就注意到这是一种将值分成集群的有效方法，如本问题底部所述。

例如：（[0] => 猫[2] =>水果 [3] => 苹果）键等同于：

第 2 - 1

键：2-0 = 2 （2>1）

第 3 - 2

键：3-2 = 1 （1=1）

我已经在问题的底部简要解释了我想要完成的任务。

数组代码如下：

$arr1 = array("cat", "Van", "fruit", "apple", "orange", "banana", "car", "car", "boat", "Bike", "truck", "cat", "dog", "bus", "van", "truck", "Sea", "ocean", "sea", "ship", "train", "Land");
$arr2 = array("cat", "fruit", "apple", "orange", "banana", "cat", "dog", "sea", "ocean", "land");
$array = array_uintersect($arr1, $arr2, 'strcasecmp');
//returns:
Array
(
    [0] => cat
    [2] => fruit
    [3] => apple
    [4] => orange
    [5] => banana
    [11] => cat
    [12] => dog
    [16] => Sea
    [17] => ocean
    [18] => sea
    [21] => Land
)

（下面）是我迄今为止编写的代码，作为我尝试分离的实现，如本问题底部所述：

$arr1 = array("cat", "Van", "fruit", "apple", "orange", "banana", "car", "car", "boat", "Bike", "truck", "cat", "dog", "bus", "van", "truck", "Sea", "ocean", "sea", "ship", "train", "Land");
$arr2 = array("cat", "fruit", "apple", "orange", "banana", "cat", "dog", "sea", "ocean", "land");
foreach($array as &$val){
$array2 = $array;
prev($array);
if(key($array2)-key($array)!==1) { //bool to determine if the difference in keys is only 1 integer apart. 
$val = array($val);
$val[] = "";
}}
unset($val);
print_r(collapse_multi_arrays($array)); //collapse_multi_arrays is a custom function I have to form a single array from multidimensional ones. 
outputs:
Array
(
    [0] => cat
    [1] => 
    [2] => fruit
    [3] => apple
    [4] => orange
    [5] => banana
    [6] => 
    [7] => cat
    [8] => dog
    [9] => 
    [10] => Sea
    [11] => ocean
    [12] => sea
    [13] => 
    [14] => Land
    [15] => 
)

（上面的输出）不确定这是否是迭代数组的最明智方法，但我想使用空值以某种方式进行分块或拆分，以便获得如下所示的内容：

Array
(
    [0] => Array
        (
            [0] => cat
        )
    [1] => Array
        (
            [2] => fruit
            [3] => apple
            [4] => orange
            [5] => banana
        )
    [2] => Array
        (
            [11] => cat
            [12] => dog
        )
    [3] => Array
        (
            [16] => Sea
            [17] => ocean
            [18] => sea
        )
    [4] => Array
        (
            [21] => Land
        )
)

我想我可以附加到每个集群到每个一个值喜欢这个：

Array
(
    [0] => cat
    [1] => fruit apple orange banana
    [2] => cat dog
    [3] => Sea ocean sea
    [4] => Land
)

/

/===

============================================================

总体解释：我总体上想做的是这样的，

由此：

Array
(
    [0] => cat
    [2] => fruit
    [3] => apple
    [4] => orange
    [5] => banana
    [11] => cat
    [12] => dog
    [16] => Sea
    [17] => ocean
    [18] => sea
    [21] => Land
)

对此：

Array
(
    [0] => cat
    [1] => fruit apple orange banana
    [2] => cat dog
    [3] => Sea ocean sea
    [4] => Land
)

这是当数组键的差异仅相隔 1 个整数时将数组值聚类追加在一起。如果数组键整数的差值大于 1，则群集附加的数组值将传递给下一个数组键，如上面的"从这个*到这个*"键值对的例子

任何帮助，建议，代码将不胜感激，因为我发现很难迭代键和值来实现这一目标，干杯。

$a = array(
    0 => 'cat',
    2 => 'fruit',
    3 => 'apple',
    4 => 'orange',
    5 => 'banana',
    11 => 'cat',
    12 => 'dog',
    16 => 'Sea',
    17 => 'ocean',
    18 => 'sea',
    21 => 'Land',
);
$last = 0;
$stack = $grouped = array();
foreach ($a as $key => $val) {
    if ($key - $last > 1) {
        $grouped[] = implode(' ', $stack);
        $stack = array();
    }
    $stack[] = $val;
    $last = $key;
}
$grouped[] = implode(' ', $stack);
print_r($grouped);