regex.md

Regular expressions re

Examples of regular expressions

Phone numbers

(|\d |\()\d\d\d(|-|.)\d\d\d(-||.)\d\d\d\d

Will match phone numbers, e.g. these strings:

• ✅718-555-3810
• ✅9175552849
• ✅1 212 555 3821
• ✅(917)5551298
• ✅212.555.8731

Anchor tags

^T

• Must start with capitalized T

$?

• Must end with ?

The anchor tags ^ and $ will match text at the start of a string and at the end of a string, respectively.

Range

h{1,2}t 

• Will match hot but not hooot

[r-t]at

• Will match rat, sat, tat, but not bat

Negation

[^cdh]are

• Will not match care, '''darebut will matchmare```

Metacharacter

• + will match the preceding character 1 or more times
• * will match the preceding character 0 or more times

o+hh will match oooooohh but not hh

?: 0 or 1 instance of the preceeding character

\d crazy sharks?

will match:

1 crazy shark and 3 crazy sharks

\w{1} \w+ \d* \w+!

• Will NOT match: I love snakes! because there's only 1 whte space between t \w+ and \w+!