Hướng dẫn all special characters javascript

I would like a RegExp that will remove all special characters from a string. I am trying something like this but it doesn’t work in IE7, though it works in Firefox.

var specialChars = "!@#$^&%*()+=-[]\/{}|:<>?,.";

for (var i = 0; i < specialChars.length; i++) {
  stringToReplace = stringToReplace.replace(new RegExp("\\" + specialChars[i], "gi"), "");
}

A detailed description of the RegExp would be helpful as well.

Toto

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asked Dec 7, 2010 at 8:47

Timothy RuhleTimothy Ruhle

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10

var desired = stringToReplace.replace(/[^\w\s]/gi, '')

As was mentioned in the comments it's easier to do this as a whitelist - replace the characters which aren't in your safelist.

The caret (^) character is the negation of the set [...], gi say global and case-insensitive (the latter is a bit redundant but I wanted to mention it) and the safelist in this example is digits, word characters, underscores (\w) and whitespace (\s).

answered Dec 7, 2010 at 8:55

annakataannakata

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Note that if you still want to exclude a set, including things like slashes and special characters you can do the following:

var outString = sourceString.replace(/[`~!@#$%^&*()_|+\-=?;:'",.<>\{\}\[\]\\\/]/gi, '');

take special note that in order to also include the "minus" character, you need to escape it with a backslash like the latter group. if you don't it will also select 0-9 which is probably undesired.

answered Jun 18, 2012 at 20:10

5

Plain Javascript regex does not handle Unicode letters.

Do not use [^\w\s], this will remove letters with accents (like àèéìòù), not to mention to Cyrillic or Chinese, letters coming from such languages will be completed removed.

You really don't want remove these letters together with all the special characters. You have two chances:

• Add in your regex all the special characters you don't want remove,
  for example: [^èéòàùì\w\s].
• Have a look at xregexp.com. XRegExp adds base support for Unicode matching via the \p{...} syntax.

var str = "Їжак::: résd,$%& adùf"
var search = XRegExp('([^?<first>\\pL ]+)');
var res = XRegExp.replace(str, search, '',"all");

console.log(res); // returns "Їжак::: resd,adf"
console.log(str.replace(/[^\w\s]/gi, '') ); // returns " rsd adf"
console.log(str.replace(/[^\wèéòàùì\s]/gi, '') ); // returns " résd adùf"

<script src="https://cdnjs.cloudflare.com/ajax/libs/xregexp/3.1.1/xregexp-all.js"></script>

answered Nov 27, 2016 at 17:25

freedevfreedev

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3

The first solution does not work for any UTF-8 alphabet. (It will cut text such as Їжак). I have managed to create a function which does not use RegExp and use good UTF-8 support in the JavaScript engine. The idea is simple if a symbol is equal in uppercase and lowercase it is a special character. The only exception is made for whitespace.

function removeSpecials(str) {
    var lower = str.toLowerCase();
    var upper = str.toUpperCase();

    var res = "";
    for(var i=0; i<lower.length; ++i) {
        if(lower[i] != upper[i] || lower[i].trim() === '')
            res += str[i];
    }
    return res;
}

Update: Please note, that this solution works only for languages where there are small and capital letters. In languages like Chinese, this won't work.

Update 2: I came to the original solution when I was working on a fuzzy search. If you also trying to remove special characters to implement search functionality, there is a better approach. Use any transliteration library which will produce you string only from Latin characters and then the simple Regexp will do all magic of removing special characters. (This will work for Chinese also and you also will receive side benefits by making Tromsø == Tromso).

answered Oct 21, 2014 at 8:50

SeagullSeagull

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using \W or [a-z0-9] regex won't work for non english languages like chinese etc.,

It's better to use all special characters in regex and exclude them from given string

str.replace(/[~`!@#$%^&*()+={}\[\];:\'\"<>.,\/\\\?-_]/g, '');

answered May 18, 2021 at 11:53

str.replace(/\s|[0-9_]|\W|[#$%^&*()]/g, "") I did sth like this. But there is some people who did it much easier like str.replace(/\W_/g,"");

answered Jun 22, 2017 at 21:16

1

I use RegexBuddy for debbuging my regexes it has almost all languages very usefull. Than copy/paste for the targeted language. Terrific tool and not very expensive.

So I copy/pasted your regex and your issue is that [,] are special characters in regex, so you need to escape them. So the regex should be : /!@#$^&%*()+=-[\x5B\x5D]\/{}|:<>?,./im

answered Dec 7, 2010 at 8:54

millebiimillebii

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@Seagull anwser (https://stackoverflow.com/a/26482552/4556619) looks good but you get undefined string in result when there are some special (turkish) characters. See example below.

let str="bənövşəyi 😟пурпурный İdÖĞ";

i slightly improve it and patch with undefined check.

function removeSpecials(str) {
    let lower = str.toLowerCase();
    let upper = str.toUpperCase();

    let res = "",i=0,n=lower.length,t;
    for(i; i<n; ++i) {
        if(lower[i] !== upper[i] || lower[i].trim() === ''){
            t=str[i];
            if(t!==undefined){
                res +=t;
            }
        }
    }
    return res;
}

answered Apr 14 at 10:17

Fuad AllFuad All

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why dont you do something like:

re = /^[a-z0-9 ]$/i;
var isValid = re.test(yourInput);

to check if your input contain any special char

answered Dec 7, 2010 at 8:57

AnDAnD

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2

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