javascript regular expressions

Question

how can i not allow these chars:

\ / " ' [ ] { } | ~ ` ^ &

using javascript regular expression pattern?

possible duplicate of http://stackoverflow.com/questions/705672/regular-expression-to-allow-a-set-of-characters-and-disallow-others — outis, Apr 03 '10 at 09:36
Also: http://stackoverflow.com/questions/756567/regular-expression-for-excluding-special-characters, http://stackoverflow.com/questions/1152844/regex-for-alphanumeric-and-the-character, http://stackoverflow.com/questions/1763071/negate-characters-in-regular-expression, http://stackoverflow.com/questions/834002/regular-expression-that-includes-all-keyboard-characters-except-and, ... — outis, Apr 03 '10 at 09:44
And (despite PHP tags): http://stackoverflow.com/questions/1778958/php-regular-expression-accept-selected-characters-only, http://stackoverflow.com/questions/878715/checking-string-for-illegal-characters-using-regular-expression. — outis, Apr 03 '10 at 09:46
What do you need it for? It looks like some sort of security instalment, but anything you do in JavaScript can be overridden by a malicious user. Also, in general, it is a lot easier to avoid injection holes by specifying a list of allowed characters, that way you are also safe from anything you hadn't thought about. — aaaaaaaaaaaa, Apr 03 '10 at 11:50

score 1 · Answer 1 · answered Apr 03 '10 at 09:26

1

Check a string contains one of these characters:

if(str.match(/[\\\/"'\[\]{}|~`^&]/)){
  alert('not valid');
}

Validate a whole string, start to end:

if(str.match(/^[^\\\/"'\[\]{}|~`^&]*$/)){
  alert('it is ok.');
}

answered Apr 03 '10 at 09:26

Kobi

2

Or to remove those characters: `str = str.replace(/[\\\/"'\[\]{}|~\`^&]/g, "");` – Anonymous Apr 03 '10 at 09:34

score 0 · Answer 2 · answered Sep 10 '20 at 14:30

0

To specifically exclude just those characters (Just prefix with backslash)

const isNotSpecial = /[^\\\/\"\'\[\]\{\}\|\~\`\^\&]/.test(myvalue);

To generally exclude all special characters

const isNotSpecial = /[^\W]/.test(myvalue);

answered Sep 10 '20 at 14:30

Steve Tomlin

score -2 · Answer 3 · answered Dec 18 '19 at 15:09

Another solution is encoding these special characters into the regular expression format.

const { RegExpCoder } = require('regexp-coder');

console.log(RegExpCoder.encodeRegExp('a^\\.()[]?+*|$z'));
// Output: 'a\^\\\.\(\)\[\]\?\+\*\|\$z'

3 Answers3