Question

列出4年内完成毕业的学生的名单，以及花费4年以上或不到4年才完成毕业的学生的名单，并通过从用户那里获得条目来打印两个列表。

我已经列出了我使用的代码也可以正常工作的列表，但是我使用了两个foreach循环来打印两个列表，但是我只想使用一个循环来减少代码的长度。下面是我用作初学者的代码。

public void Print(List<Student> students)
{
    foreach (Student student in students)
    {
        if (student.Time == "4")
        {
            Console.WriteLine($"\nPeople who completed  graduation in 4 years : \n{student.Name}");
        }
    }

    foreach (Student student in students)
    {
        if (student.Time != "4")
        {
            Console.WriteLine($"\nPeople who completed graduation in more or less than 4 years : \n{student.Name}\t{student.Time}");
        }
    }
}

Answer 1

要合并语句，仅使用一个foreach循环，请使用else。

public void Print(List students) 
{
    foreach (Student student in students)
    {
        if (student.Time =="4")
        {
            Console.WriteLine($"\nPeople who completed  graduation in 4 years : \n{student.Name}");
        }
        else
        {
            Console.WriteLine($"\nPeople who completed graduation in more or less than 4 years : \n{student.Name}\t{student.Time}");
        }
    }
}

如果您在两个列表变量之后，则可以使用linq和.Where（）

public void Print(List students) 
{
    var studentsIn4Years = students.Where(s => s.Time == "4");
    var studentsNotIn4Years = students.Where(s => s.Time != "4");

    // Do your logic here.
}

Answer 2

我认为您正在寻找这样的东西：

public void Print(List<Student> students)
{
    var studentsIn4Years = new List<string>();
    var studentsNotIn4Years = new List<string>();
    foreach (var student in students)
    {

        if (student.Time == "4")
        {
            studentsIn4Years.Add(student.Name);
        }
        else
        {
            studentsNotIn4Years.Add($"{student.Name}\t{student.Time}");
        }
    }

    Console.WriteLine($"\nPeople who completed  graduation in 4 years: ", string.Join(", ", studentsIn4Years));
    Console.WriteLine($"\nPeople who completed graduation in more or less than 4 years: ", string.Join(", ", studentsNotIn4Years));
}

但是，如果学生人数不多，我建议您考虑简单性而不是伪优化，并使用LINQ这样实现：

public void Print2(List<Student> students)
        {
            var studentsIn4Years = students.Where(s => s.Time == 4).Select(s => s.Name);
            var studentsNotIn4Years = students.Where(s => s.Time == 4).Select(s => $"{student.Name}\t{student.Time}");

            Console.WriteLine($"\nPeople who completed  graduation in 4 years: ", string.Join(", ", studentsIn4Years));
            Console.WriteLine($"\nPeople who completed graduation in more or less than 4 years: ", string.Join(", ", studentsNotIn4Years));
        }

我在列表循环中遇到问题

2 个答案: