[EMAIL PROTECTED] ("Bernie Cosell") writes:
>On 5 Dec 2001, at 11:34, [EMAIL PROTECTED] wrote:
>> But Bart said he wanted to test for 0. The test above, and several of
>> the other proposals don't distinguish between 0 and the empty string.Here's a trick: ~(~$flag||0) will map the false values undef and '' into 4294967295 (as well as the string "�"). It will pass both numeric 0 and "0" through, however. >Well, what I thought he actually said was that the flag had one of >the values 1,0,undef. In that case, ! ~(~$flag||0) is what he needs. >I suppose you could then consider it a quinary flag with two other >hidden/illegal values: true but not 1, and false but not-numeric-zero >and so in the '0' have to actually test for "was it really ZERO" >rather than the flas- but-not-numeric-zero case. The test above will yield false for '' and true for "0". >but from what he said, I'd think that bumming off of concluding "It >is not undef and not true" implies "it must have been zero" is legit >within the parameters of the challenge, no?? That must be for Bart to decide. Lars Mathiesen (U of Copenhagen CS Dep) <[EMAIL PROTECTED]> (Humour NOT marked)
