LINQ - Group By and Sum

// 假设有一个包含学生信息的集合
List<Student> students = new List<Student>
{
    new Student { Name = "Alice", Age = 18, Grade = "A" },
    new Student { Name = "Bob", Age = 19, Grade = "B" },
    new Student { Name = "Alice", Age = 20, Grade = "A" },
    new Student { Name = "Charlie", Age = 18, Grade = "C" },
    new Student { Name = "Bob", Age = 21, Grade = "B" }
};

// 使用Group By操作符按照姓名进行分组
var groupedByName = students.GroupBy(s => s.Name);

// 使用Sum操作符计算每个分组的年龄总和
foreach (var group in groupedByName)
{
    Console.WriteLine($"Name: {group.Key}, Total Age: {group.Sum(s => s.Age)}");
}

Name: Alice, Total Age: 38
Name: Bob, Total Age: 40
Name: Charlie, Total Age: 18