MetaCharacter: It is special chacter(s) which have special meaning in Regular Expression.
For Example:
*, ., /, \, ? and ^.
For Example:
*, ., /, \, ? and ^.
Sr
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Meta character
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Desctiption
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1
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[
]
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Match any character within [phc]
Means find “p” OR “h” OR “c” |
2
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-
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Range
a-z means a to z(a,b,c, ... z)
0-0 means 0 to 9
(0,1,2,3,4,5,6,7,8,9)
A-Z means A to Z(A,B,C,D
..... Z)
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3
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^
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Caret It means start with a
character
For example: ^ab (start
with “a”)
Inside the bracket if have opposite meaning.
For example: [^a](must not start with “a”)
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4
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$
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End with character
For Example
Abc$ means end with “c”
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5
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.
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The
. (period) means any character(s) in this position,
For example, ph. will find php, php-tutorial and php-tutorial-php but not aphp because it has no following character |
6
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?
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Matches
the preceding character 0 or 1 times only.
For
example:
colou?r
will find both color (0 times) and colour (1 time).
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7
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*
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Matches
the preceding character 0 or more times.
For example:
tre*
will find tree (2 times) and tread (1 time) and trough (0 times).
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8
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+
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Matches
the previous character 1 or more times.
For example:
tre+
will find tree (2 times) and tread (1 time) but NOT trough (0 times).
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9
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{n}
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Preceding
character, or character range, n times exactly.
For example:
find
a local phone number we could use [0-9]{3}-[0-9]{4} which would find any
number of the form 723-4567 OR 132-3234 OR 214-3433.
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10
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()
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To
group a character.
For
Example:
(php), will find the “php” only. |
11
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|
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Vertical
bar used for OR
(a|c)
find either “a” OR “c”
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12
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\d
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any
character in the range 0 – 9
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13
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\D
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Any
character not in between 0-9
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14
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\s
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Whitespace
or tab
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15
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\S
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Not
whitespace or tab
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16
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\w
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Alphanumeric
characters (a-z, 0-9, A-Z)
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17
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\W
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Not
alphanumeric character (a-z, 0-9, A-Z)
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