Regex: Match a string value in JSON array, split string into multiple values

In JS you could do:

var classInput = ["Cleric, Ritual Caster, Wizard"];
var classString = classInput[0];  // get the String from the Array
var classOutput = classString.split(/,\s/g); // split into and Array with separate strings

Or shorter:

var classInput = ["Cleric, Ritual Caster, Wizard"];
var classOutput = classInput[0].split(/,\s/g);

example with your list of classes: http://jsfiddle.net/bbmh1a5v/4/

P.S. "class" is often a special word in computer languages, like "id","var" and many more - if possible, try to avoid using "class" as key-word. Better try "characterClass", "profession", ...

Try this:

// Check the first string in the class property (which is assumedly an array) for a comma.
if (characterStats['class'][0].indexOf(',')) {
    // Reassign the property to the result of splitting this string at every comma. If the array has anything beyond the 0th entry, this will remove it.
    characterStats['class'] = yourBlob['class'][0].split(',')
}

Edit:

So we're checking the first entry in the array, which in your example was a big string with multiple commas. We're checking it for the indexOf a comma. If a comma exists in the string (and is past the 0th index), then we will reassign the .class property of your object to the string which is newly split into an array at each comma.

This solution addresses the data model:

{
    class: ['one,big,string,of,words']
}

and turns it into:

{
    class: ['one','big','string','of','words']
}

This solution assumes that you will never have something like this:

{
    class: ['wizard', 'sorcerer, cleric, knave']
}

In which case, you'll have to do some fancier looping and checking.