How to see if a TYPE object exists?

Blitz3D Forums/Blitz3D Programming/How to see if a TYPE object exists?

Q	(Posted 2014) [#1]

How would I go about to check if there any TYPES beyond the current type I am processing?

For example:

object.type = first type

How can I see if there is a type after this? If I assumed (wrongly) there is another and tried to process anything I'd get an error because there is no other objects after the FIRST.

type.type = after type <--- this would give an error if there is nothing after

So is there a way to check so I don't get nasty errors? :)

AngelOnFira

(Posted 2014) [#2]

I think the way I often do it is

For object.type = Each type
numofobjects=numofobjects+1
Next

Off the top of my head, that would be the easiest way to go through the whole type, then you could use that in another for loop to use first then after.

If that will not work, ill look into another way, it will help me as much as it will help you i suppose...

Yue	(Posted 2014) [#3]

;Null
if Ob.Button = Null then
  Print "Object does not exist"
End if

Rob the Great

(Posted 2014) [#4]

Just use the Null command. It will tell you if the instance you are looking at does not exist.

Type test
	Field x
End Type

Local t.test = New Test

t = After t

If t = Null
	Print "There is nothing here"
Else
	Print "This should never happen"
EndIf

EDIT: Ninja'd by Yue.

Rroff

(Posted 2014) [#5]

t.type = after t shouldn't cause an error - it should only error if you try to do something else with t without first checking via the null object as Yue explained.