.NET & JavaScript Regular Expression Tester
Target String:
Regular Expression:
case-insensitive
Pattern: l.*?y
.NET
10 matches
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Position
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Match
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| 36 | lazy |
| 48 | Lazy |
| 103 | lazy |
| 120 | lazy |
| 175 | lazy |
| 196 | lazy |
| 251 | lazy |
| 263 | lazy |
| 329 | lazy |
| 346 | lazy |
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JavaScript
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Position
|
Match
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Regular expressions are used to identify specific patterns within text. They are
useful for validating the format of email address, phone numbers, social security
numbers, and other text with distinctive patterns. They are also useful for finding,
replacing and extracting text.
Regular expressions allow patterns to be described in an abstract format. For example,
the pattern "j\w*" will find all works starting with "j", followed by zero or more
(*) words characters [a-zA-Z_0-9]. The pattern for a 5 digit number such as a zip
code is "\d{5}" where "\d" represents any digits and {5} is the quantity.
The interpretion of regular expressions can differ depending upon the programming
language or framework used. The tester above uses both Microsoft's .NET (server-side)
and JavaScript (client-side).
|
Pattern
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Finds
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| lazy
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All instances of the word "lazy"
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| l.*?y
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All words starting with "l" and ending with "y". The "." represents
any single character (except line breaks), the "*" means any quantity, and the "?"
specifices non-greedy search (end at first match).
|
| \b[tTq]\w*\b
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All strings starting with "t", "T", or "q" (\b
matches word boundary, square brackets [] defines a set of characters of which one
must match, \w matches word characters: [a-zA-Z_0-9].
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| \b\w{3}\b
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All 3-letter words.
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| \d{3}-\d{4}
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All 7 digit phone numbers with a required dash after the third digit.
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| <.*?>
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All HTML tags. "." represents "any character," "*" is any quantity, ? is non-greedy
search.
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| <(\w+>).+?</\1
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Matching pairs of HTML tags using back references. The parenthesis () create a subexpression
that can be referenced later in the expression. The \1 refers back to the first
subexpression and requires matching text. For instance, if the subexpression matched
on "h3" then the back reference \1 must also contain "h3."
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| [\w!#$%*/?|\^\{\}'~\.]+@(\w+\.)*\w{2,3}
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All email addresses (this simplified expression will allow some invalid email formats).
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