How to format a string into a local currency in JavaScript? What’s the output?
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
In the first line, we create a constant price
of a type BigInt
. This type is often used in finance as it can safely store numbers above the Number.MAX_SAFE_INTEGER
.
Then, we try to format the number 99n
into a local currency using the function toLocaleString
.
To make sure the formatting goes well, we need to pass two arguments into toLocaleString
:
- locale, for example,
en-US
, — defines the output format - object with the formatting options
One of the formatting options, could be style: 'currency'
. If you specify this option, then the number will be formatted as a currency of a specific region:
console.log(99n.toLocaleString('en-US', { style: 'currency', currency: 'USD' }));
console.log(49n.toLocaleString('de-DE', { style: 'currency', currency: 'EUR' }));
console.log(19n.toLocaleString('en-IN', { style: 'currency', currency: 'INR' }));
These numbers are formatted differently:
$99.00
49,00 €
₹19.00
But, if you look attentively into the original code snippet, you’ll notice, that the options don’t have the currency
field. Without it, the formatting doesn’t make sense and won’t work.
The error will be thrown and the conversion from BigInt
to a local currency string won't happen.
ANSWER: An error TypeError: Currency code is required with currency style.
will be logged to the console.
Get my free e-book to prepare for the technical interview or start to Learn Full-Stack JavaScript
Top comments (0)