How To Regex (Short Guide)

Regex How To:

Starts With:
	How to:
		Place the metasymbol '^' in front of your regex expression.
	Example:
		Starts with "cat":
			^cat
			would match
				i want to pet the cat
				i don't like the cat
			wouldn't match
				I think the cat is cool
				I like the cat!
		Stars with "asdf":
			^asdf
			would match
				asdfghjkl;'
			wouldn't match
				qasdf

Ends With:
	How to:
		Place the metasymbol '$' in the end of your regex expression.
	Example:
		Ends with "cat":
			cat$
			would match
				i want to pet the cat
				i don't like the cat
				dude you're such a copycat
			wouldn't match
				I think the cat is cool
				I like the cat!!

Wildcards:
	. \d \w
	Anything (Matches anything)
		How to:
			Place the metasymbol '.' anywhere to match any possible character
		Example:
			Match 3-letter words ending in "at" (first character wildcard):
				.at
				would match anything containing
					cat
					bat
					5at
					%at
				would not match
					at
					cab

	Digits (0 1 2 3 ... 9)
		How to:
			Place '\d' as a replacement for any digit.
		Example:
			Match a phone number of type (###)###-####
				(\d\d\d)\d\d\d-\d\d\d\d
				would match anything containing
					(123)456-7890
					(351)125-6382
				would not match
					(123) 456 7890
			Match a time ##:##
				\d\d:\d\d
				would match anything containing
					12:34
					01:59
				would not match
					1:59
					1234

	Word Letters (a b c ... z   _  0 1 2 ... 9 )
		How to:
			Place '\w' as a replacement for any word letter/digit.
		Example:
			Match any 5 letter word (can contain underscore or digits)
				\w\w\w\w\w
				would match anything containing
					asdfg
					as4fg
					23456
					as4f_
				would not match
					as@fg
					as fg
					~2345

Other Metasymbols:
	\ | ( ) + *
		Backslash
			It's just a metasymbol for other things, like \d \w \s
			If you want to match just a "\", then write "\\", and it will match as "\"
		Pipe (or)
			How to:
				Place a pipe | between your options
			Example:
				cat|dog|pig|goat
				would match anything containing
					cat
					dog
					pig
					goat
		Groups (useful in conjunction with everything else, semi useless alone)
			How to:
				Place the group in ( )
			Example:
				(a|c)def
				would match anything containing
					adef
					cdef
				wouldn't match
					acdef
					def
				I like (cat|dog|pig|goat)s
				would match anything containing
					I like cats
					I like dogs
					I like pigs
					I like goats

		One or more repeating
			How to:
				Place a '+' after the group or character to repeat one or more times
			Example:
				Match an a, 1 or more b's, then c
					ab+c
					would match anything containing
						abc
						abbc
						abbbbbbbbbbbbbbbbbbbbbbbc
					wouldn't match
						ac
						abdc
				Match w, then the group xy any amount of times, then z
					w(xy)+z
					would match anything containing
						wxyz
						wxyxyxyxyxyxyxyxyz
					would not match
						wxyxz
						wz
						wxy
						xyz
		Zero or more repeating
			How to:
				Place a '*' after the group or character to repeat zero or more times
			Example:
				Match an a, 0 or any number of b's, then c
					ab*c
					would match anything containing
						ac
						abc
						abbbbbbbbbbbbbbbbbbbbbbbc
					wouldn't match
						abdc