Throw Catch Try - Cany anyoen give an example ?

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bradford6

Exception handling.

Try
	Repeat
		a:+1
		DrawText (a+"is OK",400,300)
		If a>5 Throw "chunks"
		Flip
		Cls
		Delay 100
	Forever

Catch a$
	cls
	DrawText ("caught exception "+a$,400,300)
	flip
	waitmouse
EndTry

essentially it is in the format of:

try > throw > catch > end try

the try / end try block is also referred to as an Exception Block, you are trying to isolate a behavior

throw forwards a caught exception

catch handles the exception:

here is another example that is a little more useful:

Rem
Throw generates a BlitzMax exception.
End Rem

Graphics 800,600,0

Local bmax:String[]=["one","two","three","four"]
 

Try
	Repeat
		a:+1
		DrawText (bmax[a],400,300)
		If a > 4 Then Throw "BAM!" 
				Flip
		Cls
		Delay 300
	Forever

Catch ex:Object
	cls
	DrawText (ex.Tostring() ,10,300)
	flip
	waitmouse
EndTry