需要关于 php 循环的帮助以按组求和答案

【问题标题】：Need help on loop in php to sum by group需要关于 php 循环的帮助以按组求和
【发布时间】：2016-10-22 01:40:48
【问题描述】：

我需要以下帮助。需要将我的类别与金额分组，然后在底部加上总和。并计算每个类别的百分比

echo print_r($results);

Array
(
 [0] => stdClass Object
 (
 [expense_category] => Salary
 [expense_amount] => 100
 )
 [1] => stdClass Object
 (
 [expense_category] => Electricity
 [expense_amount] => 30
 )

 [2] => stdClass Object
 (
 [expense_category] => Gas
 [expense_amount] => 15
 )
 [3] => stdClass Object
 (
 [expense_category] => Gas
 [expense_amount] => 10
 )
)

我正在尝试获得以下输出：

+--------------------------+--------------+----------+
|Expense Category|cat_count|Expense Amount|Percentage|
+--------------------------+--------------+----------+
|Salary          |1        |100           |65%       |
|Electricity     |1        |30            |19%       |
|Gas             |2        |25            |16%       |
+----------------+---------+--------------+----------+
|TOTAL           |4        |155           |100%      |
+----------------+---------+--------------+----------+

以下需要帮助：

<table>
 <tr>
  <th>Expense Category</th>
  <th>cat_count</th>
  <th>Expense Amount</th>
  <th>Percentage</th>
 </tr>
 <tr>
  <td><?php echo $category ?></td>
  <td><?php echo $cat_count ?></td>
  <td><?php echo $amount ?></td>
  <td><?php echo $percent ?></td>
 </tr>
 <tr>
  <th>TOTAL</th>
  <th><?php echo $Count_Sum; ?></th>
  <th><?php echo $Cat_Sum; ?></th>
  <th>100%</th>
 </tr>
</table>

【问题讨论】：

还有……你有没有尝试自己写一些东西？或者你在找人帮你做作业？

标签： php codeigniter loops sum

【解决方案1】：

给你，答案用 cmets 注释...

<?php

$results = [
 "0" => (object)
 array (
 "expense_category" => "Salary",
 "expense_amount" => 100
 ),
 "1" => (object)
 array (
 "expense_category" => "Electricity",
 "expense_amount" => 30
 ),

 "2" => (object)
 array (
 "expense_category" => "Gas",
 "expense_amount" => 15
 ),
 "3" => (object)
 array (
 "expense_category" => "Gas",
 "expense_amount" => 10
 )
];

foreach($results as $object){
    $cat = $object->expense_category;

    // initialize
    // null coalescer ?? requires PHP >= 7
    $cat_count[$cat] = $cat_count[$cat] ?? 0;
    $amount   [$cat] = $amount   [$cat] ?? 0;

    // increment
    $cat_count[$cat]++;

    // sum
    $amount[$cat] += $object->expense_amount;
}

$amount['total'] = array_sum($amount);
// print_r($results);
?>

<table>
 <tr>
  <th>Expense Category</th>
  <th>cat_count</th>
  <th>Expense Amount</th>
  <th>Percentage</th>
 </tr>
<?php

foreach($cat_count as $cat => $count){
    $percent = $amount[$cat] / $amount['total'];
    $percent = round($percent * 100);
    echo "
        <tr>
            <td>$cat</td>
            <td>$count</td>
            <td>{$amount[$cat]}</td>
            <td>$percent</td>
        </tr>
    ";
}

?>
 <tr>
  <th>TOTAL</th>
  <th><?php echo array_sum($cat_count); ?></th>
  <th><?php echo $amount['total']; ?></th>
  <th>100%</th>
 </tr>
</table>

<table>
 <tr>
  <th>Expense Category</th>
  <th>cat_count</th>
  <th>Expense Amount</th>
  <th>Percentage</th>
 </tr>

		<tr>
			<td>Salary</td>
			<td>1</td>
			<td>100</td>
			<td>65</td>
		</tr>
	
		<tr>
			<td>Electricity</td>
			<td>1</td>
			<td>30</td>
			<td>19</td>
		</tr>
	
		<tr>
			<td>Gas</td>
			<td>2</td>
			<td>25</td>
			<td>16</td>
		</tr>
	 <tr>
  <th>TOTAL</th>
  <th>4</th>
  <th>155</th>
  <th>100%</th>
 </tr>
</table>

【讨论】：