Regular Expressions 101

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/
^app[0-9]+\s=\s\x22([0-9]+)\x22$
/
gm
^ asserts position at start of a line
app
matches the characters app literally (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)
\s matches any whitespace character (equivalent to [\r\n\t\f\v ])
= matches the character = with index 6110 (3D16 or 758) literally (case sensitive)
\s matches any whitespace character (equivalent to [\r\n\t\f\v ])
\x22 matches the character " with index 2216 (3410 or 428) literally (case sensitive)
1st Capturing Group
([0-9]+)
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)
\x22 matches the character " with index 2216 (3410 or 428) literally (case sensitive)
$ 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

/
/
gm

Test String

Substitution

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Generated Code

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Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report.
For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php