Regular Expressions 101

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/
[^a-zA-Z0-9 -._]+
/
gm
Match a single character not present in the list below
[^a-zA-Z0-9 -._]
+ 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)
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 a single character in the range between (index 32) and . (index 46) (case sensitive)
_ matches the character _ with index 9510 (5F16 or 1378) literally (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

Processing...