Override question

[XaronParticipant]

Just a simple question. When overriding a method A the method A in the base class is NOT called right? So when I want to call the base method first I have to call Super.A() ?

Is that true for the constructor (New()) as well?
Thanks!

[codifiesParticipant]

Thought you could only override an abstract (which is a shame!)

extended new calls base new…

Monkey

[crayon-5cba13f31e9a3571405076 inline="true" ] Class base Method New() Print "base new" End Method Method amethod() Print "base method" End Method End Class Class extended Extends base Method New() Print "extended new" End Method End Class Function Main() Local b:base = New base() Print "-----" Local e:extended = New extended() Print "-----" b.amethod() Print "-----" e.amethod() Print "-----" End Function

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[crayon-5cba13f31e9a3571405076 inline="true" ] Class base Method New() Print "base new" End Method Method amethod() Print "base method" End Method End Class   Class extended Extends base Method New() Print "extended new" End Method End Class   Function Main() Local b:base = New base() Print "-----" Local e:extended = New extended() Print "-----" b.amethod() Print "-----" e.amethod() Print "-----" End Function

[/crayon]

[XaronParticipant]

Thanks. I’ve extended your example. All in all base constructors are called while base methods are not (no matter if I use virtual/override for New()).

Monkey

Class base Method New() Print "base new" End Method Method amethod() Virtual Print "base method" End Method End Class Class extended Extends base Method New() Print "extended new" End Method Method amethod() Override Print "extended method" End Method End Class Function Main() Local b:base = New base() Print "-----" Local e:extended = New extended() Print "-----" b.amethod() Print "-----" e.amethod() Print "-----" End Function

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Class base   Method New()     Print "base new"   End Method     Method amethod() Virtual     Print "base method"   End Method End Class   Class extended Extends base   Method New()     Print "extended new"   End Method     Method amethod() Override     Print "extended method"   End Method End Class   Function Main()   Local b:base = New base()   Print "-----"   Local e:extended = New extended()   Print "-----"   b.amethod()   Print "-----"   e.amethod()   Print "-----" End Function

Results:

base new
—–
base new
extended new
—–
base method
—–
extended method
—–

[abakoboParticipant]

For me it makes sense because the default constructor is the initialization. And every base ‘typed’ objects should be initialized properly..
But sometimes it not logical, in the following example the new(i:int) from base does not call default constructor but new(i:int) from extended does…
Dunno what to think about this

Monkey

[crayon-5cba13f32621e419861066 inline="true" ]Class base Method New() Print "base new" 'general initilisation for all base objects End Method Method New(i:int)' virtual not necessary with new !? Print "base new"+i End Method Method amethod() Virtual Print "base method" End Method End Class Class extended Extends base Method New() override Print "extended new" End Method Method New(i:int) override Print "extended new"+i End Method Method amethod() Override Print "extended method" End Method End Class Function Main() Local b:base = New base(7) Print "-----" Local e:extended = New extended(1) Print "-----" Local b2:base = New base() Print "-----" Local e2:extended = New extended() Print "-----" b.amethod() Print "-----" e.amethod() Print "-----" End Function

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[crayon-5cba13f32621e419861066 inline="true" ]Class base Method New() Print "base new" 'general initilisation for all base objects End Method   Method New(i:int)' virtual not necessary with new !?     Print "base new"+i   End Method   Method amethod() Virtual     Print "base method"   End Method End Class Class extended Extends base   Method New() override     Print "extended new"   End Method     Method New(i:int) override     Print "extended new"+i   End Method Method amethod() Override     Print "extended method"   End Method End Class Function Main()   Local b:base = New base(7)   Print "-----"   Local e:extended = New extended(1)   Print "-----"     Local b2:base = New base() Print "-----" Local e2:extended = New extended() Print "-----"   b.amethod()   Print "-----"   e.amethod()   Print "-----" End Function

[/crayon]

[Mark SiblyKeymaster]

When overriding a method, yes, you need to call Super.Blah or it’ll never be called.

When writing a constructor, you can user Super.New(…) to explicitly call a super class constructor, in which case the call to Super.New must be the first statement in the constructor.

If your constructor does not call Super.New(…) the super class must have a ‘default’ constructor  – ie: a constructor with no params – and this will be called for you before your constructor runs. Note that a default ‘NOP’ constructor will be automatically generated for any class with NO constructors.

In monkey2, you can also use Self.New instead of Super.New at the start of a constructor. This will call a constructor in the same class instead of a super class constructor. A constructor can only call Self.New or Super.New but not both.

[XaronParticipant]

Thanks for clarification, Mark!

[Author]

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