Question

Which do you prefer?

var foo = new Foo();

foo.Prop1 = "1";
foo.Prop2 = "2";
// etc...

this.Foos.Add(foo);

or

var foo = new Foo();
this.Foos.Add(foo);

foo.Prop1 = "1";
foo.Prop2 = "2";
// etc...

Answer 1

Most of this is personal preference vs. concrete reasons but I prefer first because I find it to be the more straight forward approach. It follows the way I would think about this problem. It simply seems backwards to add it to the list and then initialize the value.

The one concrete reason I would prefer the first is it’s more resilient to changes in your code. For example if Foo was later changed from a class to a struct it would break scenario #2 but not #1. This is a pretty far corner case though.

In C# 3 and higher you could also simplify this by using a collection initializer.

this.Foos.Add(new Foo() { Prop1="1"; Prop2="2" });