連想配列の合計値数

Question

配列print_r（）を確認してください。私は「量」の価値だけを合計したいと思っています。出力は配列ではありません。これは単純な整数値でなければなりません。その結果は、4 + 3 + 9 = 16

Array 
    (
     [0] => Array 
      (
       [id] => 15 
       [portfolio_id] => 1 
       [stock_id] => 1 
       [amount] => 4 
       [date] => 04/02/2017 
       [created_at] => 2017-04-02 09:04:30 
       [updated_at] => 2017-04-02 09:04:30 
      ) 

     [1] => Array 
      (
       [id] => 14 
       [portfolio_id] => 1 
       [stock_id] => 3 
       [amount] => 3 
       [date] => 04/02/2017 
       [created_at] => 2017-04-02 09:03:40 
       [updated_at] => 2017-04-02 09:03:40 
      ) 

     [2] => Array 
      (
       [id] => 13 
       [portfolio_id] => 1 
       [stock_id] => 4 
       [amount] => 9 
       [date] => 04/02/2017 
       [created_at] => 2017-04-02 09:03:36 
       [updated_at] => 2017-04-02 09:03:36 
      ) 

    ) 

Answer 1

はこの1つを試して返される配列

Answer 2

内の値の合計を計算array_sum(array_column($input, 'amount'));

array_columnがamountキー& array_sumの値が返されてみなければなりません例：

<?php 
/** 
* Created by PhpStorm. 
* User: lenovo 
* Date: 4/2/2017 
* Time: 11:17 AM 
*/ 

    $array = array 
    (
     array("name"=>"Volvo","amount"=>22,"id"=>18), 
     array("name"=>"BMW","amount"=>15,"id"=>13), 
     array("name"=>"Saab","amount"=>5,"id"=>2), 
     array("name"=>"Land Rover","amount"=>17,"id"=>15) 
    ); 

    function sum($carry, $item) 
    { 
     $carry += $item["amount"]; 
     return $carry; 
    } 
    echo "Amount sum : " .array_reduce($array, "sum");// output : 59 

幸運。