如何使用PHP从多维数组中提取按内部某些值分组的值？

function groupByInternalValue($array, $internalValue) {
    $groupedValues = array();

    foreach ($array as $item) {
        if (isset($item[$internalValue])) {
            $value = $item[$internalValue];
            if (!isset($groupedValues[$value])) {
                $groupedValues[$value] = array();
            }
            $groupedValues[$value][] = $item;
        }
    }

    return $groupedValues;
}

// 示例数据
$students = array(
    array('name' => 'Alice', 'grade' => 'A'),
    array('name' => 'Bob', 'grade' => 'B'),
    array('name' => 'Charlie', 'grade' => 'A'),
    array('name' => 'David', 'grade' => 'C'),
    array('name' => 'Eve', 'grade' => 'B')
);

// 按照成绩分组
$groupedStudents = groupByInternalValue($students, 'grade');

// 打印结果
foreach ($groupedStudents as $grade => $students) {
    echo "Grade: " . $grade . "\n";
    foreach ($students as $student) {
        echo "- " . $student['name'] . "\n";
    }
    echo "\n";
}

Grade: A
- Alice
- Charlie

Grade: B
- Bob
- Eve

Grade: C
- David