相同键值某个字段相加

现有数组：

 [
  0 => array:2 [
    "number" => "30"
    "coins" => "230"
  ]
  1 => array:2 [
    "number" => "30"
    "coins" => "66"
  ]
  2 => array:2 [
    "number" => "29"
    "coins" => "72"
  ]
  3 => array:2 [
    "number" => "29"
    "coins" => "225"
  ]
  4 => array:2 [
    "number" => "28"
    "coins" => "213"
  ]
  5 => array:2 [
    "number" => "28"
    "coins" => "72"
  ]
]

有如下需求： number值相同的去重，并将coins值合并。

 第一种方式：

$outArr = [];
foreach ($input as $arr) {
    $number = $arr['number'];
    if (key_exists($number, $outArr)) {
        $outArr[$number] += $arr['coins'];
    } else {
        $outArr[$number] = $arr['coins'];
    }
}
输出：键值为number value值为 coins的数组  

 array:3 [
  30 => 296
  29 => 297
  28 => 285
]

方法二：

$outArr = array_reduce($input, function($result, $item) {
    if(!isset($result[$item['number']])) $result[$item['number']] = 0;
    $result[$item['number']] += $item['coins'];
    return $result;
}, array());

同样输出：键值为number value值为 coins的数组  

 array:3 [
  30 => 296
  29 => 297
  28 => 285
]

$tmp = [];
foreach($outArr as $key => $item){
  $tmp[] = [
　　　　"number" => $key,
　　　　"coins"  => $item
　　];
}
得到最终结果：

array:3 [
  0 => array:2 [
    "number" => 30
    "coins" => 296
  ]
  1 => array:2 [
    "number" => 29
    "coins" => 297
  ]
  2 => array:2 [
    "number" => 28
    "coins" => 285
  ]
]