Initialize class fields in constructor or at declaration?

Question

I\'ve been programming in C# and Java recently and I am curious where the best place is to initialize my class fields.

Should I do it at declaration?:

Answer 1

My rules:

1. Don't initialize with the default values in declaration (null, false, 0, 0.0…).
2. Prefer initialization in declaration if you don't have a constructor parameter that changes the value of the field.
3. If the value of the field changes because of a constructor parameter put the initialization in the constructors.
4. Be consistent in your practice (the most important rule).