[thelist] JavaScript -- calculating & printing

Luther, Ron Ron.Luther at COMPAQ.com
Mon Apr 9 16:01:39 CDT 2001


Hi Lon,


Good catch! ... (Yeah - I noticed that ... it didn't bother me enough to
look too deeply at - the behavior is consistent ... if you fill in both ...
metric is assumed to be your 'real' input.... and things trundle along.) 

Does that make this a "training" issue rather than a "coding" issue?  <he
says (with a very small dose of seriousness for this 'project'- but perhaps
not for some others) and ducks quickly>

I like the radio button idea though .... and I've seen a JS calculator
somewhere that I think used a drop-down to let you select any one of 40 or
so different conversions - one input, one output - and a whole lot
"prettier"!

I'm sure the "quickie" I threw up has more flaws than that ... but 'user
interface design and ease of operability' are worthwhile issues for any size
site! [even a single page] ... Basically it's a design issue that would have
to be negotiated with the client - finding the 'easiest', 'clearest' and
'most intuitive' design.... which could very well not be the one here!


Lauri's note on the "precision problem" bugged me more.  [It gets even
'cooler' - since different browser versions return different values in the
last digit to the right!  {lifted from a quick look at Danny Goodman's
JavaScript Bible}]  Welcome to floating point headaches!

While I didn't have time to fix it yet ... phone calls and work getting in
the way  ;-) ... I suspect that working with the input as a string, parsing
the number of places entered, and applying a "smart" rounding function could
do a better job. 


Lauri's last question - "What do you really do?" might be a cool thread on
thechat ... since not all of us develop public sites ... or even work in IT!


RonL.

-----Original Message-----
Lauri,

Even Ron's sample demonstrates a basic flaw. What if the user fills in BOTH
metric and imperial for a given dimension. How do you know which one was
intended?

I'm inclined to suggest using a radio select for type (meters or feet), then
inputs for the appropriate measurements... using Ron's calculator functions.
Of course they couldn't mix units once the radio was selected!





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