What does RegExp.$1 do

Question

I have come across a piece of code in JScript:

RegExp.$1

Does anybody know what it does?

If I output it on its own, I get nothing not e

Answer 1

$1 will return the first group that matches a regular expression.

In your example, the value stored in $1 is whatever was matching .+

The group is denoted by parenthesis and you can have multiples. Each saved group will just increment the digit with the $, i.e. $1, $2, $3...

Example:

If your input was __product[Version 12 Coupe] then $1 would contain Version 12 Coupe