Regular Expressions 101

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  • PCRE2 (PHP >=7.3)
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Function

  • Match
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  • Unit Tests (17)
"
^[0-9]+([,.][0-9]+)?$
"
^ asserts position at start of the string
Match a single character present in the list below
[0-9]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
1st Capturing Group
([,.][0-9]+)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
Match a single character present in the list below
[,.]
,.
matches a single character in the list ,. (case sensitive)
Match a single character present in the list below
[0-9]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
$ asserts position at the end of the string, or before the line terminator right at the end of the string (if any)
Your regular expression does not match the subject string.

Regular Expression
No Match

r"
"

Test String