Regular Expressions 101

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/
^[a-z][\w]+@[a-z]+.com$
/
gm
^ asserts position at start of a line
Match a single character present in the list below
[a-z]
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
Match a single character present in the list below
[\w]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
\w matches any word character (equivalent to [a-zA-Z0-9_])
@ matches the character @ with index 6410 (4016 or 1008) literally (case sensitive)
Match a single character present in the list below
[a-z]
+ matches the previous token between one 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)
. matches any character (except for line terminators)
com
matches the characters com 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