• Saleh@feddit.org
    link
    fedilink
    English
    arrow-up
    2
    ·
    4 days ago

    How do you do money? Especially with stuff like some prices having three or four decimals

    • jmcs@discuss.tchncs.de
      link
      fedilink
      English
      arrow-up
      10
      ·
      4 days ago

      Instead of representing $1.102 as 1.102 your store it as 1012 (or whatever precision you need) and divide by 1000 only for displaying it.

      • Saleh@feddit.org
        link
        fedilink
        English
        arrow-up
        1
        ·
        4 days ago

        So if you handle different precisions you also need to store the precision/exponent explicitly for every value. Or would you sanitise this at input and throw an exception if someone wants more precision than the program is made for?

        • jmcs@discuss.tchncs.de
          link
          fedilink
          English
          arrow-up
          6
          ·
          4 days ago

          It depends on the requirements of your app and what programming language you use. Sometimes you can get away with using a fixed precision that you can assume everywhere, but most common programming languages will have some implementation of a decimal type with variable precision if needed, so you won’t need to implement it on your own outside of university exercises.

          • Saleh@feddit.org
            link
            fedilink
            English
            arrow-up
            2
            ·
            4 days ago

            Okay thank you. I was wondering because for stuff like buying electricity, gas or certain resources, parts etc. there is prices with higher precision in cents, but the precision would not be identical over all use cases in a large company.

        • wewbull@feddit.uk
          link
          fedilink
          English
          arrow-up
          5
          ·
          4 days ago

          No exponent, or at least a common fixed exponent. The technique is called “fixed point” as opposed to “floating point”. The rationale is always to have a known level of precision.