regex tester does not work for code

If you go to, you’ll find a site that tests regular expressions (regex).

At this site,, you’ll find a tutor for regex. Now take the code and string from this page and insert them into the above page; there will be no matches.

For example, insert match(/\d+/g) or B[/B] into the Regexp: field and enter the following into the Subject string: field: Peter has 8 dollars and Jane has 15

There will be no matches. Shouldn’t the match be 3044345454 as it says on the site?

I am trying to replace double-quotes with nothing (remove double quotes from a string), and was confused when the above kept returning no matches.
string = string.replace([\"]/g, “”)

The regular expression is not match(/\d+/g) or even (/\d+/g)
The regular expression is not even /\d+/g

The regular expression is \d+

The /…/ forward slashes are used to delimit a regular expression, in a similar way that single or double quotes are used to delimit strings.
The g on the end is a flag, that specifies that the regular expression should be applied globally across the entire string.