What's the meaning of /gi in a regex?

g modifier: global. All matches (don't return on first match)

i modifier: insensitive. Case insensitive match (ignores case of [a-zA-Z])

In your case though i is immaterial as you don’t capture [a-zA-Z].

For input like !@#$ if g modifier is not there regex will return first match ! See here.

If g is there it will return the whole or whatever it can match See here.

References

• https://stackoverflow.com/a/27916097/5718493
• JavaScript RegExp gi Modifier