Bug 249986 – Intl.NumberFormat iOS bug

• Status: RESOLVED
• Resolution: INVALID
• Component: JavaScriptCore

Created attachment 464283 [details]
Two screens with a bug

Hello and Happy New Year! 
Today I found a bug in the mobile version of the Safari engine.

The problem can be seen in detail in the screenshots, but I will describe it here:

On all mobile devices running iOS 16.x, Intl.NumberFormat behaves incorrectly, putting a comma instead of a period, which leads to some errors when trying to convert a number back using Number(...).

On the desktop version of Safari, there is no such problem, and it behaves as it should.



Check code: 

const format = new Intl.NumberFormat (`us-us`, {
style: `decimal`,
useGrouping: false
minimumFractionDigits: 0,
maximumFractionDigits: 6,
});
console.log(formate.format(1.44))

[Alexey Proskuryakov]

'us-us' is a non-existent locale identifier, so Intl constructor falls back to your phone locale. You probably want to use 'en-US'.