合并数组

<?php

$arr = [
  [
    "id"=>4,
    "bank"=>[
      "sort"=>4,
      "cc"=>[
        "c2"=>5,
      ]
    ],
  ],
  [
      "id"=>3,
      "bank"=>[
        "sort"=>3,
      ]
  ]
];

function merge_arr($arr, &$res = [], $i=0)
{
  foreach ($arr as $key => $value) {
    if ($i == 0) {
      $base = [];
      merge_arr($value, $base, 1);
      $res[] = $base;
    }else if (is_array($value)) {
      merge_arr($value, $res, 1);
    }else{
      $res[$key] = $value;
    }
  }
}

$res2 = [];
merge_arr($arr, $res2);
var_dump($res2);

结果

array(2) {
  [0] =>
  array(3) {
    'id' =>
    int(4)
    'sort' =>
    int(4)
    'c2' =>
    int(5)
  }
  [1] =>
  array(2) {
    'id' =>
    int(3)
    'sort' =>
    int(3)
  }
}