Set multiple properties in a List ForEach()?

Question

Given a class:

class foo
{
    public string a = \"\";
    public int b = 0;
}

Then a generic list of them:

var list = new List         


        

Answer 1

list.ForEach(i => i.DoStuff());
public void DoStuff(this foo lambda)
{
  lambda.a="hello!"; 
  lambda.b=99;
}