QUANTIFIERS
Zero or more, optional
* matches zero or more of the previous element; ? makes it optional.
a+ one or more a. Matches "a", "aaa", but not "".a* zero or more a. Matches "aaa" and also the empty string (zero a).a? zero or one a - the a is optional. colou?r matches both color and colour.colou?r matches color and colour: the u may appear once or not at all. `*` is `+` minus the obligation: x* happily matches the empty string, which makes it dangerous alone but powerful after something concrete.
PRACTICE - 3 DRILLS 0/3 DONE
Match both color and colour.
/ /
color scheme
must match: "color"
colour scheme
must match: "colour"
colouur is wrong
must match nothing
Match "1" followed by zero or more zeros: just "1", or "10", "100", and so on.
/ /
1 10 100
must match: "1" "10" "100"
value 1000
must match: "1000"
no number
must match nothing
Match both http and https.
/ /
http first
must match: "http"
https secure
must match: "https"
ftp only
must match nothing