php foreach - group by然后在“group”更改后执行某些操作

<?php
// 假设有一个包含学生信息的数组
$students = [
    ['name' => 'Alice', 'grade' => 'A'],
    ['name' => 'Bob', 'grade' => 'B'],
    ['name' => 'Charlie', 'grade' => 'A'],
    ['name' => 'David', 'grade' => 'C'],
    ['name' => 'Eve', 'grade' => 'B']
];

// 创建一个空数组用于存储分组后的结果
$groupedStudents = [];

// 遍历学生数组
foreach ($students as $student) {
    $grade = $student['grade'];

    // 如果分组不存在，则创建一个空数组
    if (!isset($groupedStudents[$grade])) {
        $groupedStudents[$grade] = [];
    }

    // 将学生添加到对应的分组中
    $groupedStudents[$grade][] = $student;
}

// 遍历分组后的结果并执行某些操作
foreach ($groupedStudents as $grade => $group) {
    echo "Grade: $grade\n";
    foreach ($group as $student) {
        echo "Name: " . $student['name'] . "\n";
    }
    echo "\n";
}
?>

Grade: A
Name: Alice
Name: Charlie

Grade: B
Name: Bob
Name: Eve

Grade: C
Name: David