Reputation: 5189

Regular Expressions- Match Anything

How do I make an expression to match absolutely anything (including whitespaces)?
Example:

Regex: I bought _____ sheep.

Matches: I bought sheep. I bought a sheep. I bought five sheep.

I tried using (.*), but that doesn't seem to be working.

Upvotes: 476

Answers (18)

Ciabaros

Reputation: 2159

/^/

I can't see why this wouldn't be the best and indeed the simplest and most intuitive option.

Explanation: match any input that has a beginning... Every input always has a beginning and this is the only condition.

Performance: What can be faster than confirming that processing started? It should not require ANY processing -- I can't see how even one character will be looked at. Just a trivial "YES" triggered by the fact that you're asking, nothing more.

Try it yourself: Simplest Regex to Match Any Input (on regexpal.com)

Upvotes: 0

Malcolm

Reputation: 576

One option is the empty regular expression, denoted in JavaScript as /(?:)/. (You can also use new RegExp()). Logically, an empty regular expression should match strings containing "emptiness" at any position--which of course is all of them.

See this SO question and this blog post for discussion and more details.

Upvotes: 1

Montgomery Gole

Reputation: 3

I use this: (.|\n)+ works like a charm for me!

Upvotes: -3

Daniel

Reputation: 728

/.*/ works great if there are no line breaks. If it has to match line breaks, here are some solutions:

Solution	Description
`/.*/s`	`/s` (dot all flag) makes `.` (wildcard character) match anything, including line breaks. Throw in an `*` (asterisk), and it will match everything. Read more.
`/[\s\S]*/`	`\s` (whitespace metacharacter) will match any whitespace character (space; tab; line break; ...), and `\S` (opposite of `\s`) will match anything that is not a whitespace character. `*` (asterisk) will match all occurrences of the character set (Encapsulated by `[]`). Read more.

Upvotes: 31

Panu Logic

Reputation: 2263

For JavaScript the best and simplest answer would seem to be /.\*/.

As suggested by others /(.*?)/ would work as well but /.\*/ is simpler. The () inside the pattern are not needed, as far as I can see nor the ending ? to match absolutely anything (including empty strings)

NON-SOLUTIONS:

/[\s\S]/ does NOT match empty strings so it's not the solution.
/[\s\S]\*/ DOES match also empty strings. But it has a problem: If you use it in your code then you can't comment out such code because the */ is interpreted as end-of-comment.

/([\s\S]\*)/ works and does not have the comment-problem. But it is longer and more complicated to understand than /.*/.

Upvotes: 3

Cuong Le Ngoc

Reputation: 11975

If you're using JavaScript, ES2018 added the /s (dotAll) flag. With the /s flag, the dot . will match any character, including a newline.

console.log("line_1\nline_2".match(/.+/s))

Note: It's not supported by all browsers yet.

Upvotes: 8

SridharKritha

Reputation: 9611

Regex:
```
/I bought.*sheep./
```
Matches - the whole string till the end of line

I bought sheep. I bought a sheep. I bought five sheep.
Regex:
```
/I bought(.*)sheep./
```
Matches - the whole string and also capture the sub string within () for further use

I bought sheep. I bought a sheep. I bought five sheep.

I boughtsheep. I bought a sheep. I bought fivesheep.

Example using Javascript/Regex
```
'I bought sheep. I bought a sheep. I bought five sheep.'.match(/I bought(.*)sheep./)[0];
```
Output:

"I bought sheep. I bought a sheep. I bought five sheep."
```
'I bought sheep. I bought a sheep. I bought five sheep.'.match(/I bought(.*)sheep./)[1];
```
Output:

" sheep. I bought a sheep. I bought five "

Upvotes: 4

Lonnie Best

Reputation: 11354

The 2018 specification provides the s flag (alias: dotAll), so that . will match any character, including linebreaks:

const regExAll = /.*/s; //notice the 's'

let str = `
Everything
    in  this
            string
                    will
                        be
    matched. Including whitespace (even Linebreaks).
`;

console.log(`Match:`, regExAll.test(str)); //true
console.log(`Index Location:`, str.search(regExAll));

let newStr = str.replace(regExAll,"🐔");
console.log(`Replaced with:`,newStr); //Index: 0

Upvotes: 3

kjohnsonthecoder

Reputation: 181

Honestly alot of the answers are old so i found that if you simply just test any string regardless of character content with "/.*/i" will sufficiently get EVERYTHING.

Upvotes: 0

Alex Montoya

Reputation: 5099

I recommend use /(?=.*...)/g

Example

const text1 = 'I am using regex';
/(?=.*regex)/g.test(text1) // true

const text2 = 'regex is awesome';
/(?=.*regex)/g.test(text2) // true

const text3 = 'regex is util';
/(?=.*util)(?=.*regex)/g.test(text3) // true

const text4 = 'util is necessary';
/(?=.*util)(?=.*regex)/g.test(text4) // false because need regex in text

Use regex101 to test

Upvotes: 1

Sang Huynh

Reputation: 241

Because . Find a single character, except newline or line terminator.

So, to match anything, You can use like this: (.|\n)*?

Hope it helps!

Upvotes: 12

jdixon2614

Reputation: 2773

(.*?) matches anything - I've been using it for years.

Upvotes: 260

Tyler

Reputation: 1810

Choose & memorize 1 of the following!!! :)

[\s\S]*
[\w\W]*
[\d\D]*

Explanation:

\s: whitespace \S: not whitespace

\w: word \W: not word

\d: digit \D: not digit

(You can exchange the * for + if you want 1 or MORE characters [instead of 0 or more]).

BONUS EDIT:

If you want to match everything on a single line, you can use this:

[^\n]+

Explanation:

^: not

\n: linebreak

+: for 1 character or more

Upvotes: 131

oryxfea

Reputation: 141

(.*?) does not work for me. I am trying to match comments surrounded by /* */, which may contain multiple lines.

Try this:

([a]|[^a])

This regex matches a or anything else expect a. Absolutely, it means matching everything.

BTW, in my situation, /\*([a]|[^a])*/ matches C style comments.

Thank @mpen for a more concise way.

[\s\S]

Upvotes: 3

Tim Pietzcker

Reputation: 336108

Normally the dot matches any character except newlines.

So if .* isn't working, set the "dot matches newlines, too" option (or use (?s).*).

If you're using JavaScript, which doesn't have a "dotall" option, try [\s\S]*. This means "match any number of characters that are either whitespace or non-whitespace" - effectively "match any string".

Another option that only works for JavaScript (and is not recognized by any other regex flavor) is [^]* which also matches any string. But [\s\S]* seems to be more widely used, perhaps because it's more portable.

Upvotes: 462

genesis

Reputation: 50966

<?php
$str = "I bought _ sheep";
preg_match("/I bought (.*?) sheep", $str, $match);
print_r($match);
?>

http://sandbox.phpcode.eu/g/b2243.php

Upvotes: 0

Josh

Reputation: 6473

Use .*, and make sure you are using your implementations' equivalent of single-line so you will match on line endings.

There is a great explanation here -> http://www.regular-expressions.info/dot.html

Upvotes: 7

Mike Mozhaev

Reputation: 2415

Try this:

I bought (.* )?sheep

or even

I bought .*sheep

Upvotes: 30

Regular Expressions- Match Anything

Answers (18)

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