Regular Expressions 101

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  • PCRE2 (PHP >=7.3)
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1st Alternative
^ asserts position at start of a line
2nd Alternative
\D matches any character that's not a digit (equivalent to [^0-9])
1st Capturing Group
matches a digit (equivalent to [0-9])
{6} matches the previous token exactly 6 times
\D matches any character that's not a digit (equivalent to [^0-9])
3rd Alternative
$ asserts position at the end of a line
Global pattern flags
g modifier: global. All matches (don't return after first match)
m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)
Your regular expression does not match the subject string.Try launching the debugger to find out why.

Regular Expression
No Match


Test String