Can we use generic list instead of array of objects C#

Question

class Student
{
  public string ID { get; set; }
  public string Name { get; set; }
}

Student[] students = new Student[10];
int j = 0;

for(int i=0; i < 100; i++)
{
  if (some condition)
  {
    student[j].ID = anotherIDlist[i]; //some value from another list;
    student[j].Name = anotherNamelist[i]; //some value from another list;
    j++;
  }
}

Here I don't know the array length. Need it dynamic depending on the total conditions are true. Is there any efficient way of doing the same using Generic List? If so, how to do so?

Eric Lippert · Accepted Answer · 2011-04-05 16:34:01Z

5

Your coding style is reasonable and common, but notice how imperative it is. You're saying "go around this loop, mutate this collection, change this variable", building the machine that does what you want. When given the choice I prefer to code in a declarative style, and let the compiler build the machine for me. I would be inclined to write your program like this:

var query = from i in Enumerable.Range(0, 100)
            where some_condition
            select new Student() { Id = ids[i], Name = names[i] };
var students = query.ToList();

Let the compiler worry about the loops and variables and whatnot; you can concentrate on the semantics rather than the mechanisms.

answered Apr 5, 2011 at 16:34

Eric Lippert

663k185 gold badges1.3k silver badges2.1k bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Jon · Accepted Answer · 2011-04-05 16:05:15Z

3

This is really basic stuff:

var students = new List<Student>();

for(int i=0; i < 100; i++)
{
    if (some condition)
    {
        // You can produce the student to add any way you like, e.g.:
        someStudent = new Student { ID = anotherIDlist[i], Name = anotherNamelist[i] };
        students.Add(someStudent);
    }
}

answered Apr 5, 2011 at 16:05

Jon

439k85 gold badges756 silver badges820 bronze badges

1 Comment

Sri Reddy Over a year ago

Jon, I implemented your solution but then I saw Eric's and changed my code that way. But still your solution was little simpler :)

msarchet · Accepted Answer · 2011-04-05 16:05:37Z

1

List<Students> students = new List<Students>;

for(int i=0; i < 100; i++)
{
  if (some condition)
  {
    students.Add(new Student { .ID = anotherIDlist[i], .Name = anotherNamelist[i]));
  }
}

answered Apr 5, 2011 at 16:05

msarchet

15.3k2 gold badges45 silver badges66 bronze badges

Comments

BrokenGlass · Accepted Answer · 2011-04-05 16:05:39Z

1

Just replace

Student[] students = new Student[10];

with

List<Student> students = new List<Student();

and the loop with:

  if (some condition)
  {
    Student student = new Student();
    student.ID = anotherIDlist[i]; //some value from another list;
    student.Name = anotherNamelist[i]; //some value from another list;
    students.Add(student);
    j++;
  }

answered Apr 5, 2011 at 16:05

BrokenGlass

161k28 gold badges297 silver badges339 bronze badges

Comments

JaredPar · Accepted Answer · 2011-04-05 16:06:21Z

1

Yes a generic List<Student> will work great here.

List<Student> students = new List<Student>();
for(int i=0; i < 100; i++)
{
  if (some condition)
  {
    Student s = new Student();
    s.ID = anotherIDlist[i]; //some value from another list;
    s.Name = anotherNamelist[i]; //some value from another list;
    students.Add(s);
  }
}

answered Apr 5, 2011 at 16:06

JaredPar

759k152 gold badges1.3k silver badges1.5k bronze badges

Comments

Yochai Timmer · Accepted Answer · 2011-04-05 16:08:11Z

0

If you want a similar syntax :

ArrayList

answered Apr 5, 2011 at 16:08

Yochai Timmer

49.6k25 gold badges154 silver badges191 bronze badges

Collectives™ on Stack Overflow

Can we use generic list instead of array of objects C#

6 Answers 6

Comments

1 Comment

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

6 Answers 6

Comments

1 Comment

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related