// How to make regex fit below rules
- allow only letters (uppercase or smallcase), numbers, dot, underscore, dash
- at least 5 characters
- can't contain generic terms or extensions (ex: , ). .php, .mustache, .html, .js, .jpeg, .jpg, .png, .tiff, ..
e.g.
usernamex
usernamemeo
here's mine, fail to match if contain dot, underscore, dash,
and how to exclude extension string
^[a-zA-Z0-9_.-]*\w{5,}$
How to make regex fit below rules
- allow only letters (uppercase or smallcase), numbers, dot, underscore, dash
- at least 5 characters
- can't contain generic terms or extensions (ex: ., ). .php, .mustache, .html, .js, .jpeg, .jpg, .png, .tiff, ..
e.g.
username.x
username.meo
here's mine, fail to match if contain dot, underscore, dash,
and how to exclude extension string
^[a-zA-Z0-9_.-]*\w{5,}$
https://regex101./r/pT0iD8/1
Share edited Mar 17, 2016 at 0:02 user1575921 asked Mar 16, 2016 at 23:54 user1575921user1575921 1,0881 gold badge18 silver badges29 bronze badges 4-
Is
example.acceptable? – Shafizadeh Commented Mar 16, 2016 at 23:59 -
no it contains
.– user1575921 Commented Mar 17, 2016 at 0:00 - 1 Then your third rule is unclear .. – Shafizadeh Commented Mar 17, 2016 at 0:02
- thanks for reply, I update in question – user1575921 Commented Mar 17, 2016 at 0:03
2 Answers
Reset to default 10It would be something like this:
^([\w.-](?!\.(|net|html?|js|jpe?g|png)$)){5,}$
Explaining:
^ # from start
([\w.-] # \w is equal to [a-zA-Z0-9_]
(?!\. # in front can NOT be a dot followed by
( #
|net # OR net
|html? # OR htm or html # ? means optional match
|js # OR js
|jpe?g # OR jpg or jpeg
|png # OR png
)$ # block only if it is at the end
) # end of the negative lookahead
){5,} # match at least 5 characters in above conditions
$ # till the end
Hope it helps.
Though you could (possibly) wrangle it into a single regexp, it would perform really badly... you'd be much better off using a function, that can use two regular expressions.
The second part may be better off with an array check, with all the values split into an array.
function isValid(str) {
return (/^([\w\d_\.]{5,})$/i).test(str)
&& !(/\.(dll||net|exe|php|html|js|jpeg|jpg|png|tiff|gif)$/i).test(str);
}