I have a Tampermonkey script that adds some information to a browser-based game. I use a simple piece of code to add thousand separators to numbers based on the players' locales:
function nThousand(x) {
return x.toLocaleString();
}
This function is used in a lot of the code, for example:
$("#CustomStats" + stat).html(
"<b>" + texts[lang].stat_points_need + ":</b> " + nThousand(remainingPoints) + "<br />" +
"<b>" + texts[lang].money_need + ": </b>" + nThousand(remainingMoney) + "<br />" +
"<b>" + texts[lang].money_spent + ": </b>" + nThousand(currentMoney) + "<br /><br />" +
"<b>" + texts[lang].bought_points + ": </b>" + nThousand(boughtPoints) + "<br />" +
"<b>" + texts[lang].equipment_points + ": </b>" + nThousand(itemPoints) + "<br />" +
"<b>" + texts[lang].points_from_level + ": </b>" + nThousand(skillPoints) + "<br />"
);
This has worked perfectly for ages, but for some reason on one particular platform the game runs on, the script now refuses to load and gives the following error message:
Cannot read property 'toLocaleString' of undefined
I've gone back several dozen versions to make sure it wasn't something I added or changed recently, and I honestly don't even know where I would start solving this issue. The function only runs when there is a value to be localised and it's only on one specific platform the game runs on that it does this.
My question: what could be causing this and how would I go about solving this problem?
The problem isn't with toLocaleString, the issue is that somewhere you're passing undefined to your function. You'll need to figure out why that's happening through debugging. It could also be a good idea to add a guard to your function that returns an empty string if it's passed a non-string value.