sub and gsub replace with regular expressions



line = "abc"
line.sub(/Perl/, 'Ruby')    # replace first 'Perl' with 'Ruby'
line.gsub(/Python/, 'Ruby') # replace every 'Python' with 'Ruby'

1.	Regexps use elements to instruct the regular expression engine on how to find a given string.
2.	An example of a regular expression used to match a string with the String method scan.
3.	Search for a word from the very beginning
4.	Looking for a word
5.	grep(/men/)
6.	grep(/m[ae]n/)
7.	grep(/men\|man/)
8.	grep(/m(e\|a)n/)
9.	grep(/^When in/)
10.	grep(/outcast state,$/)
11.	grep(/\Aen in/)
12.	grep(/e n,\z/)
13.	grep(/[$\d\d\d$]?\d\d\d-\d\d\d\d/)
14.	grep(/colou?r/)
15.	grep(/[$\d+$]?\d+-\d+/)
16.	grep(/[$\d{3}$]?\d{3}-\d{4}/)
17.	Implementing Class and Singleton Methods
18.	Match a time
19.	Match Perl, zero or more other chars, then Python
20.	Match Perl, a space, and Python
21.	Match Perl, zero or more spaces, and Python
22.	Match Perl, one or more spaces, and Python
23.	Match Perl, whitespace characters, then Python
24.	Match Ruby, a space, and either Perl or Python
25.	Match a regular repression in if statement
26.	Replace Perl or Python with Ruby
27.	The method Regexp#match matches a regular expression against a string.
28.	MatchData-related $-variables are in $~

sub and gsub replace with regular expressions : Regexps « Development « Ruby