Graham.
Normally, variables or parameters, in order to be created at all, have to have something put into them. At least in HC they did. But with such tools as the "local" command, you can create them by simply declaring them: on mouseUp local a,b,c answer test(b) end mouseUp function test a,b,c return (param(2) = "") && (param(2) = "0") end test Both "true". Well, I am upset. Say it ain't so. These should not be "0". No way. Zero is not nothing. Craig -----Original Message----- From: Graham Samuel <livf...@mac.com> To: How to use LiveCode <use-livecode@lists.runrev.com> Sent: Mon, Oct 27, 2014 12:21 pm Subject: Is zero the same as empty? I found that if a parameter of a handler or function, or indeed a local variable, (say t1) has never had a value placed in it, then t1 = 0 is true. I was surprised by this, since I thought all unassigned variables were rendered empty by the engine, and that empty and zero were distinct. But in the same script t1 = empty is also true. Logically then, ‘empty’ is the same as ‘0’. However the statement 0 = empty evaluates to false. Furthermore if I make sure t1 is empty by put empty into t1 then 0 = t1 yields false. Am I going crazy? This issue matters to me as I am comparing numeric characters with a variable which is sometimes unassigned. I see that I must always assign a value to the variable, even it that value is empty! Is this any kind of a bug, or is it just slightly strange behaviour on the part of the engine? Graham _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
