Regular
Expressions
101
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Explanation
/
^

?
(
\d

[
1

9
]
+
\d
*

\.
\d
+

0
\.
\d
+

[
1

9
]
+
\d
*
\.
\d
+
)
$
/
gm
^
asserts position at start of a line

matches the character

with index
45
_{10}
(
2D
_{16}
or
55
_{8}
) literally (case sensitive)
1st Capturing Group
(
\d

[
1

9
]
+
\d
*

\.
\d
+

0
\.
\d
+

[
1

9
]
+
\d
*
\.
\d
+
)
1st Alternative
\d
\d
matches a digit (equivalent to
[09]
)
2nd Alternative
[
1

9
]
+
\d
*
Match a single character present in the list below
[
1

9
]
+
matches the previous token between
one
and
unlimited
times, as many times as possible, giving back as needed
(greedy)
19
matches a single character in the range between
1
(index 49)
and
9
(index 57)
(case sensitive)
\d
matches a digit (equivalent to
[09]
)
*
matches the previous token between
zero
and
unlimited
times, as many times as possible, giving back as needed
(greedy)
3rd Alternative
\.
\d
+
\.
matches the character
.
with index
46
_{10}
(
2E
_{16}
or
56
_{8}
) literally (case sensitive)
\d
matches a digit (equivalent to
[09]
)
+
matches the previous token between
one
and
unlimited
times, as many times as possible, giving back as needed
(greedy)
4th Alternative
0
\.
\d
+
0
matches the character
0
with index
48
_{10}
(
30
_{16}
or
60
_{8}
) literally (case sensitive)
\.
matches the character
.
with index
46
_{10}
(
2E
_{16}
or
56
_{8}
) literally (case sensitive)
\d
matches a digit (equivalent to
[09]
)
+
matches the previous token between
one
and
unlimited
times, as many times as possible, giving back as needed
(greedy)
5th Alternative
[
1

9
]
+
\d
*
\.
\d
+
Match a single character present in the list below
[
1

9
]
+
matches the previous token between
one
and
unlimited
times, as many times as possible, giving back as needed
(greedy)
19
matches a single character in the range between
1
(index 49)
and
9
(index 57)
(case sensitive)
\d
matches a digit (equivalent to
[09]
)
*
matches the previous token between
zero
and
unlimited
times, as many times as possible, giving back as needed
(greedy)
\.
matches the character
.
with index
46
_{10}
(
2E
_{16}
or
56
_{8}
) literally (case sensitive)
\d
matches a digit (equivalent to
[09]
)
+
matches the previous token between
one
and
unlimited
times, as many times as possible, giving back as needed
(greedy)
$
asserts position at the end of a line
Global pattern flags
g modifier:
g
lobal. All matches (don't return after first match)
m modifier:
m
ulti line. Causes
^
and
$
to match the begin/end of each line (not only begin/end of string)
Match Information
Your regular expression does not match the subject string.
Try launching the debugger to find out why.
Quick Reference
Regular Expression
v1
No Match
/
/
gm
Test String
Regular
Expressions
101
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