Converting variables? (string to numeric)

ericgnos

Hi all -

  I'm attempting to gather numeric user input, which I then need to do math to.  Nothing complicated, just adding and storing in an overall variable - no other validation or anything.

  Is there a way I can either 1) use the prompt function to store a number as numeric rather than as a string? or 2) convert a string to a numeric format?

Thanks in advance!

-Eric

TheMadExile

You can parse a numeric string into a number via the parseInt() function:


<<set $number = parseInt($numericString, 10)>>

/% You can set the return value of prompt() to a $variable and then parse that: %/
<<set
$userInput = prompt();
$number = parseInt($userInput, 10);
>>

/% Or, you can simply feed the return value of prompt() directly into parseInt(): %/
<<set $number = parseInt(prompt(), 10)>>


Either way, I'd check the return value of parseInt() with the isNaN() function, since that's what you'll have if the player decides to enter a non-numeric string for whatever reason.  For example:


<<if isNaN($number)>>
/% Not-a-Number! Yell at the player and make them do it again. %/
<<else>>
/% Seems legit, send the player on %/
<<endif>>


You could also do range validation at that point, if that's something you need/want to do.

ericgnos

That worked great for me.  Thanks for the thorough reply!

TheMadExile

Sure.  I should also have mentioned the parseFloat() function, in case you ever needed to parse a real.