How to keep the zero's when parsing two strings to a float value

Question

I'm trying to create a function that converts two strings to a float value.

Some external party created a theme with a backend where you should provide to values for a price:

• priceBeforeComma
• priceAfterComma

In the html this converts to:

<span>55,<sup>07</sup></span>

I need to do some calculations with the price as a float before splitting it up again for the html like you can see above.

I have a function that works pretty fine:

function parsePrice(price, priceDecimal) {
    return parseFloat(price + "." + priceDecimal);
}

However, the problem I'm facing is that let's say I provide 07 as the decimal like above, the leading zero is removed, returning 55,7.

There is quite a big difference between 55,07 and 55,7. I expect to get back the zero as well like 55,07.

Any help will be much appreciated.

Answer 1

Your Code is right

function parsePrice(price, priceDecimal) {
return parseFloat(price + "." + priceDecimal);
}
parsePrice("55", "07");

if you send parsePrice("55","07") so you do not need to divide it by 100 because maybe you send it 007 then you should divide it by 1000. But your code will work properly if send string

Answer 2

This might be overkill, but you could use something that provides complete control over how numbers are converted to strings, and vice versa, for example: https://github.com/alexei/sprintf.js I have not used that library, but it promises to provide the same functionality as C printf, which would allow you to keep leading zeros. See the answer to the "C" language question here: Printing leading 0's in C?

(But, as an aside, also see my comment above - generally it's better to do financial calculations in integer arithmetic rather than floating point.)

So my suggestion would be to do this instead:

function price(dollars, cents) { // adjust for your currency
   return parseInt(dollars)*100 + parseInt(cents); 
}

function dollarsAndCents(price) {
    let sign = "+";
    if (price<0) {
        sign = "-";
        price = -price;
    }
    let cents = price % 100;
    let dollars = (price-cents)/100;
    dollars = dollars.toString();
    cents = cents.toString();
    if (cents.length<2) cents = "0" + cents;
    return {sign: sign, dollars: dollars, cents: cents}
}

let price1 = price ("55", "07");
let price2 = price ("99", "99");
let total = price1 + price2;

console.log(dollarsAndCents(total))
//{ sign: '+', dollars: '155', cents: '06' }

let refund = -12345
console.log(dollarsAndCents(refund))
//{ sign: '-', dollars: '123', cents: '45' }

There you go, that's a pretty complete solution! Even handles negative amounts.

Answer 3

Floats represent 07 as 07.0, so to get this to work correctly you'll need to write it as 0.07.

Here's what worked for me:

function parsePrice(price, priceDecimal) {
    return parseFloat(price + priceDecimal); 
}

var output = parsePrice(57, 0.07); 

document.getElementById("test").innerHTML = output.toString().replace(".", ",");

<p id="test"></p>

Answer 4

You should pass in Strings to your function instead by putting quotes around your numbers. Using numbers will always have the caveat of removing any leading zeroes.

function parsePrice(price, priceDecimal) {
    return parseFloat(price + "." + priceDecimal);
}
parsePrice("55", "07");

Answer 5

Why not parse them separately as integers and add them together in the right proportions?

    function parsePrice(price, priceDecimal) {
        return parseInt(price) + (parseInt(priceDecimal) / 100);
    }

console.log(parsePrice("55", "07"));