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RegEx to delete alphanumeric and special characters inside a parenthesis

I have to delete all the conditions that match this pattern, parenthesis included
(value: "hyhyyt")
The string inside could be a number, special characters and so on.
I'm new with regex and I have come up with this expression, but it's not working. Thanks in advance to everyone.
let regex = /^(value:[a-zA-Z0-9!##$&()\\-`.+,/\"])$/g;
err.message = err.message.replace(regex, '').trim();

You can use a regex like this:
\(value: .*\)
Working demo

... edited and improved according to Edward's comment ...
The regx of the following approach tries to be both flexible/generic and precise enough.
It will, within a given string, recognize multiple (sub) patterns of '( value: " ... " )' and/or of "(value: ' ... ')". Thus its limitation, if at all, is a rare edge case of either a ") sequence enclosed by double quotes or a ') sequence enclosed by single quotes.
The regx ... /\(\s*value\s*:\s*(['"]).*?\1\s*\)/g ... itself works like that ...
\(\s*value\s*:\s* ... match a single ( followed by an optional (sequence of) whitespace(s) followed by value followed by an optional (sequence of) whitespace(s) followed by : and again followed by yet another optional (sequence of) whitespace(s),
(['"]) ... capture a single occurrence of either a single or a double quote,
.*? ... optionally match any character (sequence) in a non greedy way until the next following pattern gets matched (and which reads) ...
... \1\s*\) ... match the captured quote type followed by an optional (sequence of) whitespace(s) followed by a single ).
The regx features the global flag in order to match the pattern more than just once.
function stripParenthesizedValues(str) {
return str.replace((/\(\s*value\s*:\s*(['"]).*?\1\s*\)/g), '').trim();
}
console.log(
'stripParenthesizedValues(\' foo ((value : "hy\')t")\') =>',
`'${ stripParenthesizedValues(' foo (value : "hy\')t")') }'`
);
console.log(
"stripParenthesizedValues(\"( value : 'hy\")t' ) bar \") =>",
`'${ stripParenthesizedValues("( value : 'hy\")t' ) bar ") }'`
);
console.log(
`stripParenthesizedValues("( value : 'hy\")t ' ) foo ( value : 'hy\")t ' ) bar") =>`,
`'${ stripParenthesizedValues("( value : 'hy\")t ' ) foo ( value : 'hy\")t ' ) bar") }'`
);
.as-console-wrapper { min-height: 100%!important; top: 0; }

Use Regex to split string at array keeping all words of array [duplicate]

I need a regular expression to select all the text between two outer brackets.
Example:
START_TEXT(text here(possible text)text(possible text(more text)))END_TXT
^ ^
Result:
(text here(possible text)text(possible text(more text)))

I want to add this answer for quickreference. Feel free to update.
.NET Regex using balancing groups:
\((?>\((?<c>)|[^()]+|\)(?<-c>))*(?(c)(?!))\)
Where c is used as the depth counter.
Demo at Regexstorm.com
Stack Overflow: Using RegEx to balance match parenthesis
Wes' Puzzling Blog: Matching Balanced Constructs with .NET Regular Expressions
Greg Reinacker's Weblog: Nested Constructs in Regular Expressions
PCRE using a recursive pattern:
\((?:[^)(]+|(?R))*+\)
Demo at regex101; Or without alternation:
\((?:[^)(]*(?R)?)*+\)
Demo at regex101; Or unrolled for performance:
\([^)(]*+(?:(?R)[^)(]*)*+\)
Demo at regex101; The pattern is pasted at (?R) which represents (?0).
Perl, PHP, Notepad++, R: perl=TRUE, Python: PyPI regex module with (?V1) for Perl behaviour.
(the new version of PyPI regex package already defaults to this → DEFAULT_VERSION = VERSION1)
Ruby using subexpression calls:
With Ruby 2.0 \g<0> can be used to call full pattern.
\((?>[^)(]+|\g<0>)*\)
Demo at Rubular; Ruby 1.9 only supports capturing group recursion:
(\((?>[^)(]+|\g<1>)*\))
Demo at Rubular  (atomic grouping since Ruby 1.9.3)
JavaScript  API :: XRegExp.matchRecursive
XRegExp.matchRecursive(str, '\\(', '\\)', 'g');
Java: An interesting idea using forward references by #jaytea.
Without recursion up to 3 levels of nesting:
(JS, Java and other regex flavors)
To prevent runaway if unbalanced, with * on innermost [)(] only.
\((?:[^)(]|\((?:[^)(]|\((?:[^)(]|\([^)(]*\))*\))*\))*\)
Demo at regex101; Or unrolled for better performance (preferred).
\([^)(]*(?:\([^)(]*(?:\([^)(]*(?:\([^)(]*\)[^)(]*)*\)[^)(]*)*\)[^)(]*)*\)
Demo at regex101; Deeper nesting needs to be added as required.
Reference - What does this regex mean?
RexEgg.com - Recursive Regular Expressions
Regular-Expressions.info - Regular Expression Recursion
Mastering Regular Expressions - Jeffrey E.F. Friedl 1 2 3 4

Regular expressions are the wrong tool for the job because you are dealing with nested structures, i.e. recursion.
But there is a simple algorithm to do this, which I described in more detail in this answer to a previous question. The gist is to write code which scans through the string keeping a counter of the open parentheses which have not yet been matched by a closing parenthesis. When that counter returns to zero, then you know you've reached the final closing parenthesis.

You can use regex recursion:
\(([^()]|(?R))*\)

[^\(]*(\(.*\))[^\)]*
[^\(]* matches everything that isn't an opening bracket at the beginning of the string, (\(.*\)) captures the required substring enclosed in brackets, and [^\)]* matches everything that isn't a closing bracket at the end of the string. Note that this expression does not attempt to match brackets; a simple parser (see dehmann's answer) would be more suitable for that.

This answer explains the theoretical limitation of why regular expressions are not the right tool for this task.
Regular expressions can not do this.
Regular expressions are based on a computing model known as Finite State Automata (FSA). As the name indicates, a FSA can remember only the current state, it has no information about the previous states.
In the above diagram, S1 and S2 are two states where S1 is the starting and final step. So if we try with the string 0110 , the transition goes as follows:
0 1 1 0
-> S1 -> S2 -> S2 -> S2 ->S1
In the above steps, when we are at second S2 i.e. after parsing 01 of 0110, the FSA has no information about the previous 0 in 01 as it can only remember the current state and the next input symbol.
In the above problem, we need to know the no of opening parenthesis; this means it has to be stored at some place. But since FSAs can not do that, a regular expression can not be written.
However, an algorithm can be written to do this task. Algorithms are generally falls under Pushdown Automata (PDA). PDA is one level above of FSA. PDA has an additional stack to store some additional information. PDAs can be used to solve the above problem, because we can 'push' the opening parenthesis in the stack and 'pop' them once we encounter a closing parenthesis. If at the end, stack is empty, then opening parenthesis and closing parenthesis matches. Otherwise not.

(?<=\().*(?=\))
If you want to select text between two matching parentheses, you are out of luck with regular expressions. This is impossible(*).
This regex just returns the text between the first opening and the last closing parentheses in your string.
(*) Unless your regex engine has features like balancing groups or recursion. The number of engines that support such features is slowly growing, but they are still not a commonly available.

It is actually possible to do it using .NET regular expressions, but it is not trivial, so read carefully.
You can read a nice article here. You also may need to read up on .NET regular expressions. You can start reading here.
Angle brackets <> were used because they do not require escaping.
The regular expression looks like this:
<
[^<>]*
(
(
(?<Open><)
[^<>]*
)+
(
(?<Close-Open>>)
[^<>]*
)+
)*
(?(Open)(?!))
>

I was also stuck in this situation when dealing with nested patterns and regular-expressions is the right tool to solve such problems.
/(\((?>[^()]+|(?1))*\))/

This is the definitive regex:
\(
(?<arguments>
(
([^\(\)']*) |
(\([^\(\)']*\)) |
'(.*?)'
)*
)
\)
Example:
input: ( arg1, arg2, arg3, (arg4), '(pip' )
output: arg1, arg2, arg3, (arg4), '(pip'
note that the '(pip' is correctly managed as string.
(tried in regulator: http://sourceforge.net/projects/regulator/)

I have written a little JavaScript library called balanced to help with this task. You can accomplish this by doing
balanced.matches({
source: source,
open: '(',
close: ')'
});
You can even do replacements:
balanced.replacements({
source: source,
open: '(',
close: ')',
replace: function (source, head, tail) {
return head + source + tail;
}
});
Here's a more complex and interactive example JSFiddle.

Adding to bobble bubble's answer, there are other regex flavors where recursive constructs are supported.
Lua
Use %b() (%b{} / %b[] for curly braces / square brackets):
for s in string.gmatch("Extract (a(b)c) and ((d)f(g))", "%b()") do print(s) end (see demo)
Raku (former Perl6):
Non-overlapping multiple balanced parentheses matches:
my regex paren_any { '(' ~ ')' [ <-[()]>+ || <&paren_any> ]* }
say "Extract (a(b)c) and ((d)f(g))" ~~ m:g/<&paren_any>/;
# => (｢(a(b)c)｣ ｢((d)f(g))｣)
Overlapping multiple balanced parentheses matches:
say "Extract (a(b)c) and ((d)f(g))" ~~ m:ov:g/<&paren_any>/;
# => (｢(a(b)c)｣ ｢(b)｣ ｢((d)f(g))｣ ｢(d)｣ ｢(g)｣)
See demo.
Python re non-regex solution
See poke's answer for How to get an expression between balanced parentheses.
Java customizable non-regex solution
Here is a customizable solution allowing single character literal delimiters in Java:
public static List<String> getBalancedSubstrings(String s, Character markStart,
Character markEnd, Boolean includeMarkers)
{
List<String> subTreeList = new ArrayList<String>();
int level = 0;
int lastOpenDelimiter = -1;
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (c == markStart) {
level++;
if (level == 1) {
lastOpenDelimiter = (includeMarkers ? i : i + 1);
}
}
else if (c == markEnd) {
if (level == 1) {
subTreeList.add(s.substring(lastOpenDelimiter, (includeMarkers ? i + 1 : i)));
}
if (level > 0) level--;
}
}
return subTreeList;
}
}
Sample usage:
String s = "some text(text here(possible text)text(possible text(more text)))end text";
List<String> balanced = getBalancedSubstrings(s, '(', ')', true);
System.out.println("Balanced substrings:\n" + balanced);
// => [(text here(possible text)text(possible text(more text)))]

The regular expression using Ruby (version 1.9.3 or above):
/(?<match>\((?:\g<match>|[^()]++)*\))/
Demo on rubular

The answer depends on whether you need to match matching sets of brackets, or merely the first open to the last close in the input text.
If you need to match matching nested brackets, then you need something more than regular expressions. - see #dehmann
If it's just first open to last close see #Zach
Decide what you want to happen with:
abc ( 123 ( foobar ) def ) xyz ) ghij
You need to decide what your code needs to match in this case.

"""
Here is a simple python program showing how to use regular
expressions to write a paren-matching recursive parser.
This parser recognises items enclosed by parens, brackets,
braces and <> symbols, but is adaptable to any set of
open/close patterns. This is where the re package greatly
assists in parsing.
"""
import re
# The pattern below recognises a sequence consisting of:
# 1. Any characters not in the set of open/close strings.
# 2. One of the open/close strings.
# 3. The remainder of the string.
#
# There is no reason the opening pattern can't be the
# same as the closing pattern, so quoted strings can
# be included. However quotes are not ignored inside
# quotes. More logic is needed for that....
pat = re.compile("""
( .*? )
( \( | \) | \[ | \] | \{ | \} | \< | \> |
\' | \" | BEGIN | END | $ )
( .* )
""", re.X)
# The keys to the dictionary below are the opening strings,
# and the values are the corresponding closing strings.
# For example "(" is an opening string and ")" is its
# closing string.
matching = { "(" : ")",
"[" : "]",
"{" : "}",
"<" : ">",
'"' : '"',
"'" : "'",
"BEGIN" : "END" }
# The procedure below matches string s and returns a
# recursive list matching the nesting of the open/close
# patterns in s.
def matchnested(s, term=""):
lst = []
while True:
m = pat.match(s)
if m.group(1) != "":
lst.append(m.group(1))
if m.group(2) == term:
return lst, m.group(3)
if m.group(2) in matching:
item, s = matchnested(m.group(3), matching[m.group(2)])
lst.append(m.group(2))
lst.append(item)
lst.append(matching[m.group(2)])
else:
raise ValueError("After <<%s %s>> expected %s not %s" %
(lst, s, term, m.group(2)))
# Unit test.
if __name__ == "__main__":
for s in ("simple string",
""" "double quote" """,
""" 'single quote' """,
"one'two'three'four'five'six'seven",
"one(two(three(four)five)six)seven",
"one(two(three)four)five(six(seven)eight)nine",
"one(two)three[four]five{six}seven<eight>nine",
"one(two[three{four<five>six}seven]eight)nine",
"oneBEGINtwo(threeBEGINfourENDfive)sixENDseven",
"ERROR testing ((( mismatched ))] parens"):
print "\ninput", s
try:
lst, s = matchnested(s)
print "output", lst
except ValueError as e:
print str(e)
print "done"

You need the first and last parentheses. Use something like this:
str.indexOf('('); - it will give you first occurrence
str.lastIndexOf(')'); - last one
So you need a string between,
String searchedString = str.substring(str1.indexOf('('),str1.lastIndexOf(')');

because js regex doesn't support recursive match, i can't make balanced parentheses matching work.
so this is a simple javascript for loop version that make "method(arg)" string into array
push(number) map(test(a(a()))) bass(wow, abc)
$$(groups) filter({ type: 'ORGANIZATION', isDisabled: { $ne: true } }) pickBy(_id, type) map(test()) as(groups)
const parser = str => {
let ops = []
let method, arg
let isMethod = true
let open = []
for (const char of str) {
// skip whitespace
if (char === ' ') continue
// append method or arg string
if (char !== '(' && char !== ')') {
if (isMethod) {
(method ? (method += char) : (method = char))
} else {
(arg ? (arg += char) : (arg = char))
}
}
if (char === '(') {
// nested parenthesis should be a part of arg
if (!isMethod) arg += char
isMethod = false
open.push(char)
} else if (char === ')') {
open.pop()
// check end of arg
if (open.length < 1) {
isMethod = true
ops.push({ method, arg })
method = arg = undefined
} else {
arg += char
}
}
}
return ops
}
// const test = parser(`$$(groups) filter({ type: 'ORGANIZATION', isDisabled: { $ne: true } }) pickBy(_id, type) map(test()) as(groups)`)
const test = parser(`push(number) map(test(a(a()))) bass(wow, abc)`)
console.log(test)
the result is like
[ { method: 'push', arg: 'number' },
{ method: 'map', arg: 'test(a(a()))' },
{ method: 'bass', arg: 'wow,abc' } ]
[ { method: '$$', arg: 'groups' },
{ method: 'filter',
arg: '{type:\'ORGANIZATION\',isDisabled:{$ne:true}}' },
{ method: 'pickBy', arg: '_id,type' },
{ method: 'map', arg: 'test()' },
{ method: 'as', arg: 'groups' } ]

While so many answers mention this in some form by saying that regex does not support recursive matching and so on, the primary reason for this lies in the roots of the Theory of Computation.
Language of the form {a^nb^n | n>=0} is not regular. Regex can only match things that form part of the regular set of languages.
Read more # here

I didn't use regex since it is difficult to deal with nested code. So this snippet should be able to allow you to grab sections of code with balanced brackets:
def extract_code(data):
""" returns an array of code snippets from a string (data)"""
start_pos = None
end_pos = None
count_open = 0
count_close = 0
code_snippets = []
for i,v in enumerate(data):
if v =='{':
count_open+=1
if not start_pos:
start_pos= i
if v=='}':
count_close +=1
if count_open == count_close and not end_pos:
end_pos = i+1
if start_pos and end_pos:
code_snippets.append((start_pos,end_pos))
start_pos = None
end_pos = None
return code_snippets
I used this to extract code snippets from a text file.

This do not fully address the OP question but I though it may be useful to some coming here to search for nested structure regexp:
Parse parmeters from function string (with nested structures) in javascript
Match structures like:
matches brackets, square brackets, parentheses, single and double quotes
Here you can see generated regexp in action
/**
* get param content of function string.
* only params string should be provided without parentheses
* WORK even if some/all params are not set
* #return [param1, param2, param3]
*/
exports.getParamsSAFE = (str, nbParams = 3) => {
const nextParamReg = /^\s*((?:(?:['"([{](?:[^'"()[\]{}]*?|['"([{](?:[^'"()[\]{}]*?|['"([{][^'"()[\]{}]*?['")}\]])*?['")}\]])*?['")}\]])|[^,])*?)\s*(?:,|$)/;
const params = [];
while (str.length) { // this is to avoid a BIG performance issue in javascript regexp engine
str = str.replace(nextParamReg, (full, p1) => {
params.push(p1);
return '';
});
}
return params;
};

This might help to match balanced parenthesis.
\s*\w+[(][^+]*[)]\s*

This one also worked
re.findall(r'\(.+\)', s)

How can I program a kind of escape character myself in this regular expression?

I want to implement a function that outputs the respective strings as an array from an input string like "str1|str2#str3":
function myFunc(string) { ... }
For the input string, however, it is only necessary that str1 is present. str2 and str3 (with their delimiters) are both optional. For that I have already written a regular expression that performs a kind of split. I can not do a (normal) split because the delimiters are different characters and also the order of str1, str2, and str3 is important. This works kinda with my regex pattern. Now, I'm struggling how to extend this pattern so that you can escape the two delimiters by using \| or \#.
How exactly can I solve this best?
var strings = [
'meaning',
'meaning|description',
'meaning#id',
'meaning|description#id',
'|description',
'|description#id',
'#id',
'meaning#id|description',
'sub1\\|sub2',
'mea\\|ning|descri\\#ption',
'mea\\#ning#id',
'meaning|description#identific\\|\\#ation'
];
var pattern = /^(\w+)(?:\|(\w*))?(?:\#(\w*))?$/ // works without escaping
console.log(pattern.exec(strings[3]));
Accordingly to the problem definition, strings 0-3 and 8-11 should be valid and the rest not. myFunc(strings[3]) and should return ['meaning','description','id'] and myFunc(strings[8]) should return [sub1\|sub2,null,null]

You need to allow \\[|#] alognside the \w in the pattern replacing your \w with (?:\\[#|]|\w) pattern:
var strings = [
'meaning',
'meaning|description',
'meaning#id',
'meaning|description#id',
'|description',
'|description#id',
'#id',
'meaning#id|description',
'sub1\\|sub2',
'mea\\|ning|descri\\#ption',
'mea\\#ning#id',
'meaning|description#identific\\|\\#ation'
];
var pattern = /^((?:\\[#|]|\w)+)(?:\|((?:\\[#|]|\w)*))?(?:#((?:\\[#|]|\w)*))?$/;
for (var s of strings) {
if (pattern.test(s)) {
console.log(s, "=> MATCHES");
} else {
console.log(s, "=> FAIL");
}
}
Pattern details
^ - string start
((?:\\[#|]|\w)+) - Group 1: 1 or more repetitions of \ followed with # or | or a word char
(?:\|((?:\\[#|]|\w)*))? - an optional group matching 1 or 0 occurrences of
\| - a | char
((?:\\[#|]|\w)*) - Group 2: 0 or more repetitions of \ followed with # or | or a word char
(?:#((?:\\[#|]|\w)*))? - an optional group matching 1 or 0 occurrences of
# - a # char
((?:\\[#|]|\w)*) Group 3: 0 or more repetitions of \ followed with # or | or a word char
$ - end of string.

My guess is that you wish to split all your strings, for which we'd be adding those delimiters in a char class maybe, similar to:
([|#\\]+)?([\w]+)
If we don't, we might want to do so for validations, otherwise our validation would become very complicated as the combinations would increase.
const regex = /([|#\\]+)?([\w]+)/gm;
const str = `meaning
meaning|description
meaning#id
meaning|description#id
|description
|description#id
#id
meaning#id|description
sub1\\|sub2
mea\\|ning|descri\\#ption
mea\\#ning#id
meaning|description#identific\\|\\#ation`;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
Demo

Seems like what you're looking for may be this?
((?:\\#|\\\||[^\|#])*)*
Explanation:
Matches all sets that include "\#", "\|", or any character except "#" and "|".
https://regexr.com/4fr68

Regex: Negative Lookbehind + Lookahead in Javascript

I'll try to wrap my head around this regex which works on server side.
new RegExp(/(?<!:\s*\w*)\w+(?=\s*[,}])/g)
it walkes through a string which look like this:
{Product{id{$lt:10,$gt:20},title,other,categories{id,name}}}
It matches all keys which have no subkeys or values. But this do not work in Javascript because Javascript do not allow Lookbehind Parts of a RegExp. I wonder if there is a workaround in Javascript for this. All what I have read is for Lookbehind only but not for Lookbehind+Lookahead.
You can play around with it here. regex101.com
Edit: Some more info: This regexp ist part of an parser which parses a minimalistic query language - a chimera of GraphQL and MondoDB-Queries.
There is function where a string goes in like
{Product{id{$lt:10,$gt:20},title,other,categories{id,name}}}
and outputs an object. all keys which have no subkeys or values in fact which ends with an ',' or an '}' are replaced with :true. At the end the Output look like this:
{
Product: {
id: { $lt: 10 },
title: true,
categories: {
name: true
}
}
}
I am trying to make it client-side.

I think this solves you problem
const regex = /[{,]\s*\w+(?=[,}])/g
const str = `{Product{id{$lt:10,$gt:20},title,other,categories{id,name}}}`
const result = str.replace(regex, (...a) => `${a[0]}:true`)
console.log(result)

Not sure the results you're trying to get, but this is your regex
without using the lookbehind assertion.
The whole idea, incase you're interested, is to move the match position
beyond the stuff you don't want to match.
This does that.
(?: # -------------
( : \s* \w+ ) # (1), Move past this
| # or,
( \w+ ) # (2), To get to this
) # -------------
(?= \s* [,}] ) # Common lookahead assertion
Generally, you just use the JS callback capability to find out what matched.
var regex = /(?:(:\s*\w+)|(\w+))(?=\s*[,}])/g;
var str = '{Product{id{$lt:10,$gt:20},title,other,categories/{id,name}}}';
var newString = str.replace(
regex,
function(match, p1, p2) { // Callback function
if (p1) return p1; // Group 1, return it unchanged
return p2 + ':true'; // Group 2, modifiy it
});
console.log(newString);
Output
{Product{id{$lt:10,$gt:20},title:true,other:true,categories/{id:true,name:true}}}

Escape string for use in Javascript regex [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Is there a RegExp.escape function in Javascript?
I am trying to build a javascript regex based on user input:
function FindString(input) {
var reg = new RegExp('' + input + '');
// [snip] perform search
}
But the regex will not work correctly when the user input contains a ? or * because they are interpreted as regex specials. In fact, if the user puts an unbalanced ( or [ in their string, the regex isn't even valid.
What is the javascript function to correctly escape all special characters for use in regex?

Short 'n Sweet (Updated 2021)
To escape the RegExp itself:
function escapeRegExp(string) {
return string.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'); // $& means the whole matched string
}
To escape a replacement string:
function escapeReplacement(string) {
return string.replace(/\$/g, '$$$$');
}
Example
All escaped RegExp characters:
escapeRegExp("All of these should be escaped: \ ^ $ * + ? . ( ) | { } [ ]");
>>> "All of these should be escaped: \\ \^ \$ \* \+ \? \. \( \) \| \{ \} \[ \] "
Find & replace a string:
var haystack = "I love $x!";
var needle = "$x";
var safeNeedle = escapeRegExp(needle); // "\\$x"
var replacement = "$100 bills"
var safeReplacement = escapeReplacement(replacement); // "$$100 bills"
haystack.replace(
new RegExp(safeNeedle, 'g'),
escapeReplacement(safeReplacement),
);
// "I love $100 bills!"
(NOTE: the above is not the original answer; it was edited to show the one from MDN. This means it does not match what you will find in the code in the below npm, and does not match what is shown in the below long answer. The comments are also now confusing. My recommendation: use the above, or get it from MDN, and ignore the rest of this answer. -Darren,Nov 2019)
Install
Available on npm as escape-string-regexp
npm install --save escape-string-regexp
Note
See MDN: Javascript Guide: Regular Expressions
Other symbols (~`!## ...) MAY be escaped without consequence, but are not required to be.
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Test Case: A typical url
escapeRegExp("/path/to/resource.html?search=query");
>>> "\/path\/to\/resource\.html\?search=query"
The Long Answer
If you're going to use the function above at least link to this stack overflow post in your code's documentation so that it doesn't look like crazy hard-to-test voodoo.
var escapeRegExp;
(function () {
// Referring to the table here:
// https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/regexp
// these characters should be escaped
// \ ^ $ * + ? . ( ) | { } [ ]
// These characters only have special meaning inside of brackets
// they do not need to be escaped, but they MAY be escaped
// without any adverse effects (to the best of my knowledge and casual testing)
// : ! , =
// my test "~!##$%^&*(){}[]`/=?+\|-_;:'\",<.>".match(/[\#]/g)
var specials = [
// order matters for these
"-"
, "["
, "]"
// order doesn't matter for any of these
, "/"
, "{"
, "}"
, "("
, ")"
, "*"
, "+"
, "?"
, "."
, "\\"
, "^"
, "$"
, "|"
]
// I choose to escape every character with '\'
// even though only some strictly require it when inside of []
, regex = RegExp('[' + specials.join('\\') + ']', 'g')
;
escapeRegExp = function (str) {
return str.replace(regex, "\\$&");
};
// test escapeRegExp("/path/to/res?search=this.that")
}());