How to update an object in a List<> in C#

c# asp.net list generics
Burjua picture Burjua · Aug 25, 2011 · Viewed 292.4k times · Source

I have a List<> of custom objects.

I need to find an object in this list by some property which is unique and update another property of this object.

What is the quickest way to do it?

Answer

Random Dev picture Random Dev · Aug 25, 2011

Using Linq to find the object you can do:

var obj = myList.FirstOrDefault(x => x.MyProperty == myValue);
if (obj != null) obj.OtherProperty = newValue;

But in this case you might want to save the List into a Dictionary and use this instead:

// ... define after getting the List/Enumerable/whatever
var dict = myList.ToDictionary(x => x.MyProperty);
// ... somewhere in code
MyObject found;
if (dict.TryGetValue(myValue, out found)) found.OtherProperty = newValue;

Related questions

Convert string to List<string> in one line?

I have a string: var names = "Brian,Joe,Chris"; Is there a way to convert this to a List<string> delimited by , in one line?

Read More
Select method in List<t> Collection

I have an asp.net application, and now I am using datasets for data manipulation. I recently started to convert this dataset to a List collection. But, in some places it doesn't work. One is that in my old version …

Read More
How to get values of selected items in CheckBoxList with foreach in ASP.NET C#?

I have a CheckBoxList like this: <asp:CheckBoxList ID="CBLGold" runat="server" CssClass="cbl"> <asp:ListItem Value="TGJU"> TG </asp:ListItem> <asp:ListItem Value="GOLDOZ"> Gold </asp:ListItem> <asp:…

Read More