C# expression body with {get;} vs without [duplicate]

Answer 1

The first line of code -

public SomeListViewModel SearchSomeModel => new ShowSomeViewModel{...};

means that it will create a new instance of ShowSomeViewModel every time that you try to get it.
It is the equivalent of:

public SomeListViewModel SearchSomeModel {
    get {return new ShowSomeViewModel{...};}
}

On the other hand the

public SomeListViewModel SearchSomeModel {get;} =  new ShowSomeViewModel{...};

means you are setting a default value.