Regular Expression Examples

^ The ^ (circumflex or caret) outside square brackets means look only at the beginning of the target string, for example, ^Win will not find Windows in STRING1 but ^Moz will find Mozilla.

$ The $ (dollar) means look only at the end of the target string, for example, fox$ will find a match in 'silver fox' since it appears at the end of the string but not in 'the fox jumped over the moon'. . The . (period) means any character(s) in this position, for example, ton. will find tons, tone and tonneau but not wanton because it has no following character.

/abc/ - Matches the first occurrence of the 'abc' string.

 /12/ - Matches the first occurrence of the '12' string.

/ab*c/ - Matches the first occurrence of the string that begins with 'a', followed by any number of 'b' and ends with 'c'. Possible strings: 'ac', 'abc', 'abbc', 'abbbc', ...

/ab+c/ - Matches the first occurrence of the string that begins with 'a', followed by at least one 'b' and ends with 'c'. Possible strings: 'abc', 'abbc', 'abbbc', ...

 /ab{2,}c/ - Matches the first occurrence of the string that begins with 'a', followed by two or more 'b' and ends with 'c'. Possible strings: 'abbc', 'abbbc', 'abbbbc', ...

/(ab)*c/ - Matches the first occurrence of the string that begins with some 'ab', followed by 'c'. Possible strings: 'c', 'abc', 'ababc', 'abababc', ...

/(ab)+c/ - Matches the first occurrence of the string that begins with one or more 'ab', followed by 'c'. Possible strings: 'abc', 'ababc', 'abababc', ...

/(ab){2,}c/ - Matches the first occurrence of the string that begins with two or more 'ab', followed by 'c'. Possible strings: 'ababc', 'abababc', 'ababababc', ...

/ab?c/ - Matches the first occurrence of the string that begins with 'a', followed by at most one 'b' and ends with 'c'. Possible strings: 'ac' 'abc'.

 /ab{1,2}c/ - Matches the first occurrence of the string that begins with 'a', followed by one or two 'b' and ends with 'c'. Possible strings: 'abc' 'abbc'.

 /ab{2}c/ - Matches the first occurrence of the 'abbc' string.

/(ab)?c/ - Matches the first occurrence of the string that begins at most one 'ab', followed by 'c'. Possible strings: 'c' 'abc'.

/(ab){1,2}c/ - Matches the first occurrence of the string that begins with one or two 'ab', followed by 'c'. Possible strings: 'abc' 'ababc'.

/(ab){2}c/ - Matches the first occurrence of the 'ababc' string.

/^whole$/ - Checks if the analyzed string is 'whole'.

 /^ca(t|r)$/ - Checks if the analyzed string is 'cat' or 'car'.

/[abc]/ - Matches the first occurrence of the 'a', 'b' or 'c' character.

 /[ab]{1,2}/ - Matches the first occurrence of the 'a', 'b', 'aa', 'ab', 'ba' or 'bb' string.

 /[^abc]/ - Matches the first occurrence of a character that is not 'a', 'b' and 'c'.

/\d/ - Matches the first occurrence of any digit.

/\d{1,2}/ - Matches the first occurrence of one or two digits. /\d|[1-9]\d/ - Matches the first occurrence of an integer between 0 and 99. Similar to the previous regular expression, but '00', '01', '02', ..., '09' are not allowed.

 /(\+|-)?(\d|[1-9]\d)/ - Matches the first occurrence of an integer between 0 and 99 with or without sign. Note that the '\' character needs to be used before the '+' character, because the '+' character has special meaning in regular expressions.

Several special characters can be used in a regular expression. With these characters various patterns can be specified.
The following table lists the supported special characters.

Character	Description
\	The backslash character has two different meanings, depending on the character that follows. For an alphanumeric character, it indicates that it is a special character. For example, /d/ - matches a 'd' character, but /\d/ - matches a digit character. Some of the alphanumeric characters have no meaning together with the backslash character. Using the backslash character with these characters causes an error. For a non-alphanumeric character, it indicates that it is a normal character. It can be useful if you need a pattern matching for a special character. For example, /a*/ - matches any number of 'a' character, but /a\*/- matches only the 'a*' string.
^	Indicates that the match must start at the beginning of the input string. If the multiline flag is specified, the match can start after a \r or \n character. For example, /^m/ has no match in 'woman', but has a match in 'man'
$	Indicates that the match must end at the end of the input string. If the multiline flag is specified, the match can end at a \r or \n character. For example, /m$/ has no match in 'format', but has a match in 'form'.
*	Matches the preceding item zero or more times. Equivalent to {0,}. For example, pattern: /b*a/g - input: 'hubba and bubba'.
+	Matches the preceding item at least one time. Equivalent to {1,}. For example, pattern: /b+a/g - input: 'hubba and bubba'.
?	Matches the preceding item zero or one time. Equivalent to {0,1}. For example, pattern: /b?a/g - input: 'hubba and bubba'.
.	(dot) Matches any single character except the newline characters (\n, \r, \u2028 or \u2029). Use the [\s\S] pattern to match any character including newline characters. For example, pattern: /.s/g - input: 'sail the seas'.
(pattern)	Matches pattern, and stores the match (called as capturing parentheses, captured subexpression or parenthesized subexpressions). The stored parts of a match can be retrieved through the $1, $2, ... , $9 properties.
(?:pattern)	Matches pattern, but does not store the match (called as non-capturing parentheses, non-captured subexpression or non-parenthesized subexpressions).
pattern1(?=pattern2)	Matches pattern1 only when pattern1 is followed by pattern2. For example, /a(?=b)/g matches 'a' letter only if the 'a' letter is followed by a 'b' letter. Pattern: /a(?=b)/g - input: 'abracadabra'.
pattern1(?!pattern2)	Matches pattern1 only when pattern1 is not followed by pattern2. For example, /a(!=b)/g matches 'a' letter only if the 'a' letter is not followed by a 'b' letter. Pattern: /a(!=b)/g - input: 'abracadabra'.
pattern1|pattern2	Matches pattern1 or pattern2. For example, pattern: /(a|r)/g - input: 'agreed'.
{n}	Where n is a nonnegative integer. Matches the preceding item exactly n times. For example, pattern: /9{2}/g - input: '79799799979999'.
{n,}	Where n is a nonnegative integer. Matches the preceding item at least n times. For example, pattern: /9{2,}/g - input: '79799799979999'.
{n,m}	Where n and m are nonnegative integers and n <= m. Matches the preceding item at least n and at most m times. For example, pattern: /9{2,3}/g - input: '79799799979999'.
[xyz]	A character set. Matches any one of the enclosed characters. For example, pattern: /[adr]/g - input: 'agreed'.
[^xyz]	A negated character set. Matches any character that is not enclosed. For example, pattern: /[^adr]/g - input: 'agreed'.
[a-z]	A range of characters. Matches any character in the specified range. For example, pattern: /[a-d]/g - input: 'agreed'.
[^a-z]	A negated range of characters. Matches any character that is not in the specified range. For example, pattern: /[^a-d]/g - input: 'agreed'.
\b	Matches a word boundary, not a backspace! The [\b] pattern matches a backspace. A word boundary can be at the beginning or end of a word, it is the position between a word and a non-word character (see the \w and \W patterns). For example, pattern: /\ba/g - input: 'an abracadabra'.
\B	Matches a non-word boundary. For example, pattern: /\Ba/g - input: 'an abracadabra'.
\cx	Where x is a character (letter) from A-Z or a-z. Matches the control character. For example, \cI matches Control-I (tab).
\d	Matches a digit. Equivalent to [0-9]. For example, pattern: /\d/g - input: 'a1b23c'.
\D	Matches a non-digit. Equivalent to [^0-9]. For example, pattern: /\D/g - input: 'a1b23c'.
\f	Matches a form-feed character. Equivalent to \x0c. (The form-feed character causes the printer to advance one page length or to the top of the next page.)
\n	Matches a newline character. Equivalent to \x0a.
\r	Matches a carriage return character. Equivalent to \x0d.
\s	Matches any white space character. For example, pattern: /s\sa/g - input: 'Thats all'.
\S	Matches any non-white space character. For example, pattern: /\Sa/g - input: 'Thats all'.
\t	Matches a tab character. Equivalent to \x09.
\v	Matches a vertical tab character. Equivalent to \x0b.
\w	Matches an alphanumeric (letter or number) character including underscore. Equivalent to [A-Za-z0-9_]. For example, pattern: /\w+/g - input: '5+23'.
\W	Matches a non-word (non-alphanumeric) character. Equivalent to [^A-Za-z0-9_]. For example, pattern: /\W+/g - input: '5+23'.
\n	n is a positive integer. If the entire regular pattern contains at least n captured subexpressions before (see (pattern)), then the \n is a back reference to the nth subexpression, else n must be an octal code (see \ooo). For example, pattern: /(\d+)\+\1/g - input: '23+12, 23+23, 12+12+23'.
\0	Matches a NULL character.
\ooo	Matches a character specified by its octal code ooo. For example (the code of the '+' character is \053), pattern: /\053/g - input: '23+12'.
\xhh	Matches a character specified by its hexadecimal code hh. For example (the code of the '+' character is \x2B), pattern: /\x2B/g - input: '23+12'.
\uhhhh	Matches a character specified by its Unicode code hhhh. For example (the code of the '+' character is \u002B), pattern: /\u002B/g - input: '23+12'.

Examples:

/a/

Mary had a little lamb.

And everywhere that Mary

went, the lamb was sure

to go.

/Mary/

Mary had a little lamb.

And everywhere that Mary

went, the lamb was sure

to go.

/.*/

Special characters must be escaped.*

/\.\*/

Special characters must be escaped.*

/^Mary/

Mary had a little lamb.

And everywhere that Mary

went, the lamb was sure

to go.

/Mary$/

Mary had a little lamb.

And everywhere that Mary

went, the lamb was sure

to go.

/.a/ 

Mary had a little lamb.

And everywhere that Mary

went, the lamb was sure

to go.

/(Mary)( )(had)/ 

Mary had a little lamb.

And everywhere that Mary

went, the lamb was sure

to go.

/[a-z]a/ 

Mary had a little lamb.

And everywhere that Mary

went, the lamb was sure

to go.

/[^a-z]a/ 

Mary had a little lamb.

And everywhere that Mary

went, the lamb was sure

to go.

/cat|dog|bird/

The pet store sold cats, dogs, and birds.

/=first|second=/

=first first= # =second second= # =first= # =second=

/(=)(first)|(second)(=)/

=first first= # =second second= # =first= # =second=

/=(first|second)=/

=first first= # =second second= # =first= # =second=

/@(=+=)*@/ 

Match with zero in the middle: @@

Subexpresion occurs, but...: @=+=ABC@

Lots of occurrences: @=+==+==+==+==+=@

Must repeat entire pattern: @=+==+=+==+=@

/A+B*C?D/

AAAD

ABBBBCD

BBBCD

ABCCD

AAABBBC

/a{5} b{,6} c{4,8}/

aaaaa bbbbb ccccc

aaa bbb ccc

aaaaa bbbbbbbbbbbbbb ccccc

/a+ b{3,} c?/

aaaaa bbbbb ccccc

aaa bbb ccc

aaaaa bbbbbbbbbbbbbb ccccc

/a{5} b{6,} c{4,8}/

aaaaa bbbbb ccccc

aaa bbb ccc

aaaaa bbbbbbbbbbbbbb ccccc

/(abc|xyz) \1/

jkl abc xyz

jkl xyz abc

jkl abc abc

jkl xyz xyz

/(abc|xyz) (abc|xyz)/

jkl abc xyz

jkl xyz abc

jkl abc abc

jkl xyz xyz

/th.*s/

-- I want to match the words that start

-- with 'th' and end with 's'.

this

thus

thistle

this line matches too much

/th[^s]*./

-- I want to match the words that start

-- with 'th' and end with 's'.

this

thus

thistle

this line matches too much