Question

php 2维数组 把dates的值相同的sum相加起来放在另一个数组

Array
(
[0] => Array
(
[sum] => 10
[dates] => 201301
)
[1] => Array
(
[sum] => 3323
[dates] => 201301
)
[2] => Array
(
[sum] => 372
[dates] => 201302
)
[2] => Array
(
[sum] => 372
[dates] => 201302
)
[2] => Array
(
[sum] => 372
[dates] => 201302
)
[2] => Array
(
[sum] => 372
[dates] => 201302
)
[2] => Array
(
[sum] => 372
[dates] => 201302
)
[2] => Array
(
[sum] => 372
[dates] => 201302
)

）
复制错了 键值只有0.1.2 下面的不是

Answer 1

试编写代码如下：

<?php
$arr = Array
(
"0" => Array
(
"sum" => 10,
"dates" => 201301
),
"1" => Array
(
"sum" => 3323,
"dates" => 201301
),
"2" => Array
(
"sum" => 372,
"dates" => 201302
)
);
$aResult = array();
foreach($arr as $value)
{
$date = $value['dates'];
$sum = $value['sum'];
if(array_key_exists($date,$aResult))
{
$aResult[$date] += $sum;
} else
{
$aResult[$date] = $sum;
}
}
echo '<pre>';
print_r($aResult);
echo '</pre>';
?>

运行结果：

Array
(
[201301] => 3333
[201302] => 372
)

Answer 2

装B写法:
function e($v){
global $a;
$a[$v['dates']]+=$v['sum'];
}
array_walk($arr,'e');
print_r($a);