PHP数组中子项的平均值

Question

Array (
  [JohnDoe] => Array (
  [id] => 23
  [name] => JohnDoe
  [logintimes] => 30
)
 [JaneDoe] => Array (
  [id] => 26
  [name] => JaneDoe
  [logintimes] => 9
)
 [Smith] => Array (
  [id] => 35
  [name] => Smith
  [logintimes] => 9
 )
)

我如何通过向对方添加登录时间（然后找到它们的平均值？）

Answer 1

循环并获得

非常简单

$counter = 0;
$total = 0;
foreach($array as $row) {
    $counter++;
    $total += $row['logintimes'];
}
echo $total / $counter;

Answer 2

您也可以使用array_sum和array_map执行此操作：

$sum = array_sum(array_map(function($item) { 
    return $item['logintimes']; 
}, $your_array));

echo $sum / count ($your_array);

Answer 3

为了完整性，PHP＆gt; = 5.5.0：

$average = array_sum(array_column($array, 'logintimes')) / count($array);

Answer 4

您必须遍历数组，并使用子数组引用来总计logintimes值。完成后，您只需将logintimes的总和除以数组项的数量。

示例：

<?php
$users = array(
    "JohnDoe" => array(
        "id" => 23,
        "name" => "JohnDoe",
        "logintimes" => 30
    ),
    "JaneDoe" => array(
        "id" => 23,
        "name" => "JaneDoe",
        "logintimes" => 9
    ),
    "Smith" => array(
        "id" => 35,
        "name" => "Smith",
        "logintimes" => 9
    )
);

$count = 0;
$total = 0;
foreach($users as $user => $values) {
    $count++;
    $total += $values['logintimes'];
}
$average = $total / $count;

echo $average;  //Output 16

工作示例：http://codepad.org/uHpJnODv

Answer 5

认为此解决方案应该更有效（PHP 5.5 +）：

 <?php
$users = array(
    "JohnDoe" => array(
        "id" => 23,
        "name" => "JohnDoe",
        "logintimes" => 30
    ),
    "JaneDoe" => array(
        "id" => 23,
        "name" => "JaneDoe",
        "logintimes" => 9
    ),
    "Smith" => array(
        "id" => 35,
        "name" => "Smith",
        "logintimes" => 9
    )
);

$count = count($users);
$average = array_column($users , 'logintimes') / $count;

echo $average;  //Output 16