Javascript Regex Whitelist with character limit

Question

I'm trying to add a character limit clause to this white list regex approach

str = str.replace(/[^A-Za-z-_0-9 ]/g, "");

Is it possible and how do I do it?

I'm unsure of what you want to do, exactly. Can you provide an example string and describe your desired behavior? I'm guessing you want to limit the length of the whole string, or you want to match only runs of matched characters that exceed (or are under) a certain length. — apsillers, Jun 08 '12 at 05:10
For example, suppose you have a limit of 10: for the string "aaa%$?!@^&*()~`bbb" should the run of twelve invalid characters in the middle *not* be removed because there is more than 10 matched characters there? — apsillers, Jun 08 '12 at 05:27

score 3 · Answer 1 · answered Jun 08 '12 at 04:53

3

Use a quantifier to specify the limit.

If you want a maximum (10 for example) do this:

str = str.replace(/[^A-Za-z-_0-9 ]{,10}/g, "");

A minimum:

str = str.replace(/[^A-Za-z-_0-9 ]{10,}/g, "");

A range:

str = str.replace(/[^A-Za-z-_0-9 ]{8,10}/g, "");

An exact quantity:

str = str.replace(/[^A-Za-z-_0-9 ]{10}/g, "");

answered Jun 08 '12 at 04:53

Paul

2

I tried this solution, it didn't work, which is why I came here :(. tag = tag.replace(/[^A-Za-z-_0-9 ]{0,5}/g, ""); Although that still whitelist the characters properly, it doesn't enforce the character limit to the string – shiva8 Jun 08 '12 at 05:00

score 0 · Accepted Answer · edited Aug 01 '12 at 17:09

0

str = str.replace(/[^A-Za-z-_0-9\s]/g, "").substring(0,10);  //At most 10 chars

edited Aug 01 '12 at 17:09

Bart

answered Jun 08 '12 at 05:02

1

Came out with the answer before you did, but thanks this works. Sometimes simple solutions are the best :D – shiva8 Jun 08 '12 at 20:01

2 Answers2