PHP -根据项目名称求和的数字

$data = [
    '项目A' => 10,
    '项目B' => 20,
    '项目A' => 5, // 注意：如果有重复的项目名称，后面的值会覆盖前面的值
    '项目C' => 15,
];

$sumByProject = [];

foreach ($data as $project => $value) {
    if (!isset($sumByProject[$project])) {
        $sumByProject[$project] = 0;
    }
    $sumByProject[$project] += $value;
}

print_r($sumByProject);

Array
(
    [项目A] => 15
    [项目B] => 20
    [项目C] => 15
)

foreach ($data as $project => $value) {
    $sumByProject[$project] = (isset($sumByProject[$project]) ? $sumByProject[$project] : 0) + $value;
}