Variable add ?

Comments

• greyelf

  August 2015 edited August 2015

  You have run into an issue that many people new to HTML have and that is that by default anything that is entered into either a prompt or an input field is considered by the web-browser to be a String (Text) value even if the contents of that value looks like a number or a date.
  
  So lets assume the Reader of your story entered a 1 for force, a 2 for intelligence, a 3 for agility and a 4 for endurence.
  
  If the web-browser accepted these values as numbers then your $for+$int+$agi+$endu would be 1 + 2 + 3 + 4 which would equal 10 but this is not what happened.
  
  Instead the web-browser accepted then as String (Text) so your $for+$int+$agi+$endu would be "1" + "2" + "3" + "4" which would equal "1234", as the following test shows:

  <<set $for to prompt(" force ?")>>
  <<set $int to prompt(" intelligence ?")>>
  <<set $agi to prompt(" agility ?")>>
  <<set $endu to prompt(" endurence ?")>>
  
  add them: <<print $for+$int+$agi+$endu>>
  

  
  What you need to do is to first convert each of those Strings into numbers which you can do this using the Javascript parseInt fuction but this leads into a second issue, what happens if the Reader enters a value like "ABC" for force instead of a number.
  
  You will first need to test the values that the Reader has entered to check that they are actually numerical before you can convert them. The following is a basic example of how to use Javascript's isNaN function to do this, although it does not test for all the things that could go wrong like the Reader entering a number with a decimal point instead of an integer:

  <<set $for to prompt(" force ?")>>
  <<set $int to prompt(" intelligence ?")>>
  <<set $agi to prompt(" agility ?")>>
  <<set $endu to prompt(" endurence ?")>>
  
  <<if not isNaN($for)>><<set $for to parseInt($for)>><</if>>
  <<if not isNaN($int)>><<set $int to parseInt($int)>><</if>>
  <<if not isNaN($agi)>><<set $agi to parseInt($agi)>><</if>>
  <<if not isNaN($endu)>><<set $endu to parseInt($endu)>><</if>>
  
  add them: <<print $for+$int+$agi+$endu>>
  

  
  note: Instead of using the prompt function you could use SugarCube's <<textbox>> macro.
• thierrys

  August 2015

  Salutation Greyelf,
  
  i ve change for textbox, more beautifull
  
  i use <<if not isNaN($for)>><<set $for to parseInt($for)>><</if>> ...
  even i don't know how it work...that ligne do the job... magic of the code
  
  
  thank's for answer. Fast and accurate !
  unfortunatly ... ll be back
  
  Thierry
• greyelf

  August 2015

  I included links to the documentation for both isNaN and parseInt functions in my last comment.
  
  isNaN checks to see if a value within a String (piece of Text) is equal to a number:

  isNaN("ABCDE") returns false because the characters in "ABCDE" are not numeric.
  
  isNaN("12345") returns true because the characters in "12345" are numeric.
  

  
  parseInt converts a String that contains numeric characters (1234567890) into a number (i.
• thierrys

  August 2015

  Start programms and technical english at more than 40 is not so easy
  it s more clear, with your explanation. Thank you.
  
  I ve still a lot of questions ... don't care to each one or you will lost too much time
  
  best regards
  Thierry