Regular Expressions 101

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/
<img src=([a-zA-Z0-9_\-\s\.\"=\/:%,()]*class=\"[a-zA-Z0-9_\-\s\.\"=\/:%,()]*lazy[a-zA-Z0-9_\-\s\.\"=\/:%,()]*)
/
gm
<img src=
matches the characters <img src= literally (case sensitive)
1st Capturing Group
([a-zA-Z0-9_\-\s\.\"=\/:%,()]*class=\"[a-zA-Z0-9_\-\s\.\"=\/:%,()]*lazy[a-zA-Z0-9_\-\s\.\"=\/:%,()]*)
Match a single character present in the list below
[a-zA-Z0-9_\-\s\.\"=\/:%,()]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
_ matches the character _ with index 9510 (5F16 or 1378) literally (case sensitive)
\- matches the character - with index 4510 (2D16 or 558) literally (case sensitive)
\s matches any whitespace character (equivalent to [\r\n\t\f\v ])
\. matches the character . with index 4610 (2E16 or 568) literally (case sensitive)
\" matches the character " with index 3410 (2216 or 428) literally (case sensitive)
= matches the character = with index 6110 (3D16 or 758) literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
:%,()
matches a single character in the list :%,() (case sensitive)
class=
matches the characters class= literally (case sensitive)
\" matches the character " with index 3410 (2216 or 428) literally (case sensitive)
Match a single character present in the list below
[a-zA-Z0-9_\-\s\.\"=\/:%,()]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
_ matches the character _ with index 9510 (5F16 or 1378) literally (case sensitive)
\- matches the character - with index 4510 (2D16 or 558) literally (case sensitive)
\s matches any whitespace character (equivalent to [\r\n\t\f\v ])
\. matches the character . with index 4610 (2E16 or 568) literally (case sensitive)
\" matches the character " with index 3410 (2216 or 428) literally (case sensitive)
= matches the character = with index 6110 (3D16 or 758) literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
:%,()
matches a single character in the list :%,() (case sensitive)
lazy
matches the characters lazy literally (case sensitive)
Match a single character present in the list below
[a-zA-Z0-9_\-\s\.\"=\/:%,()]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
_ matches the character _ with index 9510 (5F16 or 1378) literally (case sensitive)
\- matches the character - with index 4510 (2D16 or 558) literally (case sensitive)
\s matches any whitespace character (equivalent to [\r\n\t\f\v ])
\. matches the character . with index 4610 (2E16 or 568) literally (case sensitive)
\" matches the character " with index 3410 (2216 or 428) literally (case sensitive)
= matches the character = with index 6110 (3D16 or 758) literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
:%,()
matches a single character in the list :%,() (case sensitive)
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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Code Generator

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