LINQ按不同输出分组

var students = new List<Student>
{
    new Student { Name = "Alice", Age = 20, Grade = "A" },
    new Student { Name = "Bob", Age = 21, Grade = "B" },
    new Student { Name = "Charlie", Age = 20, Grade = "A" },
    new Student { Name = "David", Age = 22, Grade = "C" },
    new Student { Name = "Emily", Age = 21, Grade = "B" }
};

var groupedStudents = from student in students
                      group student by student.Grade into studentGroup
                      select new { Grade = studentGroup.Key, Students = studentGroup };

foreach (var group in groupedStudents)
{
    Console.WriteLine("Grade: " + group.Grade);
    foreach (var student in group.Students)
    {
        Console.WriteLine("Name: " + student.Name + ", Age: " + student.Age);
    }
    Console.WriteLine();
}