Regular Expressions 101

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Community Patterns

2

\tilde \alpha

PCRE2 (PHP >=7.3)
\tilde \alpha
Submitted by anonymous - 5 months ago
2

tst

PCRE2 (PHP >=7.3)
test
Submitted by anonymous - 4 months ago
1

Exponential Value Identification

PCRE2 (PHP >=7.3)
Exponential Value Identification
Submitted by Nimit Bhagat - 4 months ago
2

Command line parser

.NET 7.0 (C#)
Supports parameters such as keys and values, also parameters enclosed in quotes.
Submitted by Pavel Bashkardin - 3 months ago (Last modified 3 months ago)
2

GitHub URL Parser

ECMAScript (JavaScript)
A regular expression for extracting the author, repository name, and optional branch from a GitHub repository or tree URL. Handles both HTTP(S) and direct GitHub links.
Submitted by Xain - 2 months ago
2

Quiz_1

PCRE2 (PHP >=7.3)
Check if a string contains the word word in it (case insensitive). If you have no idea, I guess you could try /word/.
Submitted by anonymous - a month ago
2

Quiz_17_Start_before_end

PCRE2 (PHP >=7.3)
Only match lines with the text start, unless text end appears prior to start. Note: end may or may not be in the string. Match start line_end; and don't match line_end; start
Submitted by anonymous - a month ago
2

Quiz_16_Repeated_Words

PCRE2 (PHP >=7.3)
I'd like to know if a text contains words with 4 characters or more which are repeated 3 or more times in the text (anywhere in the text). If so, set one (and only one) backreference for each word.
Submitted by anonymous - a month ago
2

Quiz_15_Not_surrounded_by_digits

PCRE2 (PHP >=7.3)
Replace every . (dot) with a - (hyphen) except when the dot is surrounded by digits. E.g.: .a.b.1.2. should become -a-b-1.2-
Submitted by anonymous - a month ago
2

Quiz_14_Spam_filter

PCRE2 (PHP >=7.3)
Match a string that contains any of the following substrings: http://, www., porn, or credit card. But don't match the text if it contains one of: not allowed, filter, or mirc. Don't use word boundaries (anywhere in the text is fine). If you need help, try reading this.
Submitted by anonymous - a month ago
2

Quiz_13_Match_Alternating_0s_And_1s_In_Any_Order

PCRE2 (PHP >=7.3)
I'm trying to match bit sequences which are alternating between 1 and 0 and never have more than one 1 or 0 in a row. They can be single digits. Try matching this: 0101010, 1010101010 or 1
Submitted by anonymous - a month ago
2

Quiz_12_Match_Any_Number_Between_0-100

PCRE2 (PHP >=7.3)
Could you help me validate my input and only match positive integers between the range of 0 and 100? There can be several numbers in a string which I would want to retrieve. Try out these example strings: ...
Submitted by anonymous - a month ago
0

Verify and match e-mail address

PCRE (PHP <7.3)
no description available
Submitted by Josh K - 11 years ago
-1

Simple replacing. Replaced first folder in path to file.

PCRE (PHP <7.3)
Used with Java regexp. F.e. you can use replaceAll("regexp", "filePath").
Submitted by E.ch. - 11 years ago
0

Simple

ECMAScript (JavaScript)
no description available
Submitted by anonymous - 11 years ago
1

Anom

ECMAScript (JavaScript)
no description available
Submitted by anonymous - 11 years ago
1

bridal quality

PCRE (PHP <7.3)
no description available
Submitted by mine - 11 years ago
1

why this matches?

PCRE (PHP <7.3)
no description available
Submitted by romans - 11 years ago
1

{if}{endif} matcher

PCRE (PHP <7.3)
no description available
Submitted by anonymous - 11 years ago
0

Dotted-decimal IPv4 address

PCRE (PHP <7.3)
Validates an IPv4 address for use as a URI host as defined in RFC-3986.
Submitted by ezzatron - 11 years ago
1...7475767778...900

Community Library Entry

2

Regular Expression
PCRE2 (PHP >=7.3)

/
\b(?<!-)(?:\d{1,2}|100)\b
/
gmi
Open regex in editor

Description

Could you help me validate my input and only match positive integers between the range of 0 and 100?

There can be several numbers in a string which I would want to retrieve.

Try out these example strings:

Sam has 200 apples. He gives Todd 20 and Mary 125. The weather is -5 C today, but will be +5 C tomorrow.

Submitted by anonymous - a month ago