Get length of a LONG?

Comments

• Phil Pilgrim (PhiPi) Posts: 23,514

  2014-06-13 21:30 edited 2014-06-13 21:30

  Using Simple_Numbers.spin as num:
  

  length := strsize(num.dec(your_long))

  
  -Phil
• Ariba Posts: 2,694

  2014-06-14 15:07 edited 2014-06-14 15:07

  Or include a little subroutine like this:

  PRI DecSize(value) : n
    repeat
      n++
    until (value/=10) < 1
  

  (not tested)
  
  length := DecSize(myLong)
  
  Andy
• JonnyMac Posts: 9,566

  2014-06-14 18:12 edited 2014-06-14 18:12

  Another possibility, though not as trim or sexy as what's been suggested:
  

  pub digits(value)
  
    case value
      0..9       : return 1
      10..99     : return 2
      100..999   : return 3
      1000..9999 : return 4
      other      : return 5
  

  
  
  
  For numbers, I like to right-justify in displayed. I have this bit of code in my serial and LCD objects:
  

  pub rjdec(val, width, pchar) | tmpval, pad
  
  '' Print right-justified decimal value
  '' -- val is value to print
  '' -- width is width of (padded) field for value
  '' -- pchar is [leading] pad character (usually "0" or " ")
  
  '  Original code by Dave Hein
  '  Added (with modifications) to FDS by Jon McPhalen
  
    if (val => 0)                                                                 ' if positive
      tmpval := val                                                               '  copy value
      pad := width - 1                                                            '  make room for 1 digit
    else
      if (val == negx)                                                            '  if max negative
        tmpval := posx                                                            '    use max positive for width
      else                                                                        '  else
        tmpval := -val                                                            '    make positive
      pad := width - 2                                                            '  make room for sign and 1 digit
     
    repeat while (tmpval => 10)                                                   ' adjust pad for value width > 1
      pad--
      tmpval /= 10
       
    repeat pad                                                                    ' print pad
      tx(pchar)
  
    dec(val)                                                                      ' print value
  
• Beau Schwabe Posts: 6,576

  2014-06-14 19:14 edited 2014-06-14 19:14

  Too bad there isn't a ... LOG(10) function
• Phil Pilgrim (PhiPi) Posts: 23,514

  2014-06-14 21:26 edited 2014-06-14 21:26

  Beau Schwabe wrote:

  Too bad there isn't a ... LOG(10) function

  It could be done that way:
  

  log₁₀(x) = log₂(x) / log₂(10)

  
  But after the ROM table lookups, interpolations, and division, I wouldn't trust it to be accurate near the power-of-ten boundaries.
  
  -Phil
• Peter Jakacki Posts: 10,193

  2014-06-14 23:56 edited 2014-06-14 23:56

  eagletalontim wrote: »

  If I have a LONG that totals 12345, how can I get the length of the LONG which would be 5? I am trying to clear the characters after the number is display on an LCD without clearing all the spaces. Sometimes the length will be 2 numbers, sometimes it will be 5 numbers.

  
  Sometimes those digits mean something such as 000 where it would be important to know that 3 digits were entered. If this number being displayed is a keypad entry then simply count each digit as it is entered. The other thing is that I am a bit worried about is that you are so worried about clearing the number on the LCD in such a precise manner, what is the problem with clearing 5 digits all the time?
  The problem of course with all out answers is that the question in couched in such a narrow context which can only mean a narrow answer, which might just miss the mark.