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