in javascript/emca script 7, is there a to get how many an inputs a class has?

i'm currently working on a project which requires the user to generate a relative decent chunk of data to be saved locally. and this will be repeated data which is similar, but unique strings.

what i'm currently working with is a system where i have an input that is more or less:

function createCustomJob() {
    let dateFrom = prompt("Enter date from:");
    let dateTo = prompt("Enter date to:");
    let description = prompt("Enter job description:");
    let isCurrentPosition = confirm("Is it a current position?");
    let publicOrPrivate = prompt("Enter public or private:");
    let position = prompt("Enter job position:");
    let name = prompt("Enter job name:");

    let obj = new Obj(dateFrom, dateTo, description, isCurrentPosition, publicOrPrivate, position, name);

i however want to instead build the input using html, so i'm wondering is there some sorta way to get how many values a constructor is getting? something such as Obj.length that works? before the first object is created so i can dynamically create the proper amount of html inputs needed, or would this be something i instead need to "hard code"?

I highly would suggest you use a html form and use the submit handler to get all data that the user/you enters.

The way you are currently implementing it is very hard to maintain in the future.

As of the question:
You can simply use an array in the constructor and then you have direct access to the amount of the input variables.

Or

You can create an object and use the object keys for a named approach to better retrieve the data.

Use Object.keys(obj), Object.values(obj) or even Object.entries(obj) to access the variables.

Mozilla has always good references to look into:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries?retiredLocale=de

If you really want to do what your question is about, you can use the spread operator, here an example to use:

class Test{
    constructor(...rest){
        console.log(rest)
    }
}