Question

Let’s have an object created in a getter like this :

public class Class1
{
       public string Id { get; set; }
       public string Oz { get; set; }
       public string Poznamka { get; set; }

       public Object object
       {
             get
             {
                  // maybe some more code
                  return new Object { Id = Id, poznamla = Poznamka, Oz = OZ };
             }
        }
 }

Or should I rather create a Method that will create and return the object ?

Answer 1

Properties look like fields but they are methods. This has been known to cause a phenomenal amount of confusion. When a programmer sees code that appears to be accessing a field, there are many assumptions that the programmer makes that may not be true for a property.So there are some common properties design guidelines.

1. Avoid returning different values from the property getter. If called multiple times in a row, a property method may return a different value each time; a field returns the same value each time.

2. A property method may require additional memory or return a reference to something that is not actually part of the object’s state, so modifying the returned object has no effect on the original object; querying a field always returns a reference to an object that is guaranteed to be part of the original object’s state. Working with a property that returns a copy can be very confusing to developers, and this characteristic is frequently not documented.

3. Consider that a property cannot be passed as an out or ref parameter to a method; a field can.

4. Avoid long running property getters. A property method can take a long time to execute; field access always completes immediately.

5. Avoid throwing exceptions from getters.

6. Do preserve previous values if a property setter throws an exception

7. Avoid observable side effects.

8. Allow properties to be set in any order even if this results in a temporary invalid state of objects.

Sources

“CLR via C#“, Jeffrey Richter. Chapter 9. Defining Properties Intelligently

“Framework Design Guidelines” 2nd edition, Brad Abrams, Krzysztof Cwalina, Chapter 5.2 Property Design