Update a dcl Lisp

[Steven P]

15 hours ago, mhy3sx said:

I try this but is not working

 

Couple of things to think about. Lists in LISP tend to start at item 0, and not item 1 (in a list A B C D the 'A' is in position 0) - you'll have to check the if statements above are looking for 1 to 4.. (in a list A B C D E that would be 'B' 'C' 'D' and 'E') - I think the same is true with DCL

 

The nil error you are getting - if you don't select an item in the drop down box then the value of MyAnswer will be the default value you set at the start of the list, in this case, 'nil', if you arn't searching for 'nil' in your cond statements then the values of T1 and T2 won't be set. So you could set MyAnswer at the start to a value, 0 perhaps, or put a t condition in the conds (if none of the above match then do this) - an internet search will help you there.

 

 

 

... so set the default MyAnswer to 0 instead of nil and set the 'conds' to 0 - 3 and not 1 - 4