CODEWITHSUNDEEP
c#
Janet
Janet

Reputation: 1411

Add items to array within classes

I am new to programming in C#. I guess it might be a very easy solution which I am not aware of .

Suppose I have a class file 

using System;
using System.Collections.Generic;

namespace sharepointproject1
{
    public partial class School
    {
        public students[] students { get; set; }
    }

    public partial class student
    {
        public marks[] marks;
        public extraactivites[] extraactivities;
    }
    public partial class marks
    {
        public int m1 { get; set; }
        public int m2 { get; set; }
    }
    public partial class extraactivities
    {
        public decimal m5;
        public decimal m6;

    }
}

Now in aspx.cs file how do I add marks to the array declared?

namespace sharepointproject1
{
    public partial class testing : usercontrol
    {
        School school = new school();
        protected void Page_Load(object sender, EventArgs e)
        {
            school.students[0].marks[0].mark1 = 45;
        }
    }
}

I need to dynamically add items to it at run time. How do I do that? Do I have to change the array to list array in the class file..Hope I am making some sense out of my question.Later I need to bind the marks to the gridview.

Please help!

Upvotes: 0

Views: 2045

Answers (4)

Darren Lewis
Darren Lewis

Reputation: 8488

Unless you're stuck for some reason in .NET 1.0 I'd strongly recommend looking at the Collection classes and then generics available in .NET. These will allow you to replace the array[] declarations with List where T is a .NET type. e.g

public class Student
{
    public List<Mark> Marks{get;set;}
}

public class Mark
{
    public int SomePropertyA { get; set; }
    public int SomePropertyB { get; set; }
}

Upvotes: 0

Marcote
Marcote

Reputation: 3095

My advice is forget arrays and use List or List<T> which is the generic List. Not only because solves the dynamic part of of your problem, but also has better performance avoiding box and unboxing.

Upvotes: 1

Alexei Levenkov
Alexei Levenkov

Reputation: 100527

You need to change Array to something that can grow dynamically like List<>. It may be better option to add methods like AddMark(marks mark) to student class and perform Add operation inside the class.

Upvotes: 0

Jon Skeet
Jon Skeet

Reputation: 1500155

Arrays have a fixed size - use a more flexible collection such as List<T>, which will grow as you need it to.

Eric Lippert has a good blog post about why arrays should be considered somewhat harmful.

Additionally:

  • You should look into the .NET naming conventions
  • Only use partial classes when you actually need to, which I suspect you don't here
  • Don't expose public fields; use properties instead. However, don't just expose everything as a property: consider more encapsulation. You don't necessarily want callers to be able to replace whole collections, but just (say) add or remove students, or access them by index.
  • Consider making some of your classes immutable (most obviously Marks and ExtraActivities)

Upvotes: 6

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