3-parameter g,i,m__ regular expressions for JavaScript regular expressions

Web site for testing:

Http://www.pagecolumn.com/tool/regtest.htm
the string used for testing is:

Bsdfefsdf
Aaa
Dfsdfa
AAA G: Global lookup Mode

No g will only match 1, plus g to find all the matches

Regular expression:

/aaa/

The results match the following:
Bsdfefsdf
Aaa
Dfsdfa

Aaa

Regular expression:

/aaa/g

The result matches the following:
Bsdfefsdf
Aaa
Dfsdfa
Aaa I: Do not distinguish between sizes

Regular expression:

/aaa/i

The result matches the following:
Bsdfefsdf
Aaa
Dfsdfa
Aaa
m: Multi-line Lookup mode

The default ^ and $ match only the beginning and end of the string, such as:

Regular expression:

/^aaa/ 

will not match the test string, because the test data 4 lines as a whole, the beginning is BSD rather than AAA

Regular expressions

The results match the following:
Bsdfefsdf
Aaa
Dfsdfa
Aaa

With the M argument, ^ and $ can match the beginning and end of each row, but only the first one, such as:

The results match the following:
Bsdfefsdf
Aaa
Dfsdfa
Aaa