VSCode Regex: Capturing area codes differs from regexone.com's Exercise 2 behavior

Question

I'm learning regex on regexone.com. In exercise 2: Matching Phone Numbers, The same patterns work differently between regexone.com and VSCode's find/replace feature.

The exercise shows these test cases:

415-555-1234
650-555-2345
(416)555-3456
202 555 4567
4035555678
1 416 555 9292

The goal is to capture only the area codes (the first three contiguous numbers) for each line which are :

415
650 
416
202 
403
416

On regexone.com, the pattern (\d{3}) successfully captures these area codes in all cases.

However, in VSCode's find/replace, this same pattern doesn't work as expected - particularly with the (416) case and the "1 416" case.

I've tried variations like:

• (?:1 )?(\d{3})
• ^.{0,2}(\d{3})
• \(?(\d{3})

But none perfectly match regexone.com's behaviour. What's the correct pattern for VSCode that will capture area codes in all these formats? And why does VSCode handle this differently?