Question

I have a Person object:

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
    public string Address { get; set; }
    public double Height { get; set; }
    public bool IsTest { get; set; }
}

Then I have a list filled with different Person objects.

I want to know is there a way to use ternary operator with GroupBy in LINQ depending on some property of object. For example:

var groupedPersons = persons.GroupBy(person => person.IsTest ? 
                      new {
                              person.Name, 
                              person.Age, 
                              person.Address
                           } 
                     : new {
                              person.Name, 
                              person.Age, 
                              person.Address, 
                              person.Height}).ToList();

But unfortunately that doesn’t work, gives me exception

Type of conditional expression cannot be determined because there is
no implicit conversion between ‘AnonymousType#1’ and ‘AnonymousType#2’

Is this achievable at all and how?

Thanks

EDIT: Tried this, but not working.

var groupedPersons = persons.GroupBy(person => person.OnTest ? 
                     new Person { 
                                   Address = person.Address, 
                                   Name = person.Name, 
                                   Age = person.Age } 
                     : new Person { 
                                   Address= person.Address, 
                                   Name = person.Name, 
                                   Age = person.Age , 
                                   Height = person.Height}).ToList();

EDIT: Got it to work, look at my answer

Answer 1

Ok, after trying some examples shown here I realized that this is not gonna work and I got it to work other way. Here’s an example how I did it:

var groupedPersons = 
       persons.GroupBy(
                 person =>
                      person.Name + "|" +
                      person.Age.ToString() + "|" +
                      person.Address + "|" +
                      (person.IsTest ? null : person.Height.ToString())
      .ToList();

So if there’s a Person with property IsTest = false then it uses person.Height to group also.