diff options
Diffstat (limited to 'activesupport/lib/active_support/core_ext/string/access.rb')
-rw-r--r-- | activesupport/lib/active_support/core_ext/string/access.rb | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/core_ext/string/access.rb b/activesupport/lib/active_support/core_ext/string/access.rb index 23aaee9c43..5c32a2453d 100644 --- a/activesupport/lib/active_support/core_ext/string/access.rb +++ b/activesupport/lib/active_support/core_ext/string/access.rb @@ -1,18 +1,79 @@ require 'active_support/multibyte' class String + # If you pass a single Fixnum, returns a substring of one character at that + # position. The first character of the string is at position 0, the next at + # position 1, and so on. If a range is supplied, a substring containing + # characters at offsets given by the range is returned. In both cases, if an + # offset is negative, it is counted from the end of the string. Returns nil + # if the initial offset falls outside the string. Returns an empty string if + # the beginning of the range is greater than the end of the string. + # + # str = "hello" + # str.at(0) #=> "h" + # str.at(1..3) #=> "ell" + # str.at(-2) #=> "l" + # str.at(-2..-1) #=> "lo" + # str.at(5) #=> nil + # str.at(5..-1) #=> "" + # + # If a Regexp is given, the matching portion of the string is returned. + # If a String is given, that given string is returned if it occurs in + # the string. In both cases, nil is returned if there is no match. + # + # str = "hello" + # str.at(/lo/) #=> "lo" + # str.at(/ol/) #=> nil + # str.at("lo") #=> "lo" + # str.at("ol") #=> nil def at(position) self[position] end + # Returns a substring from the given position to the end of the string. + # If the position is negative, it is counted from the end of the string. + # + # str = "hello" + # str.from(0) #=> "hello" + # str.from(3) #=> "lo" + # str.from(-2) #=> "lo" + # + # You can mix it with +to+ method and do fun things like: + # + # str = "hello" + # str.from(0).to(-1) #=> "hello" + # str.from(1).to(-2) #=> "ell" def from(position) self[position..-1] end + # Returns a substring from the beginning of the string to the given position. + # If the position is negative, it is counted from the end of the string. + # + # str = "hello" + # str.to(0) #=> "h" + # str.to(3) #=> "hell" + # str.to(-2) #=> "hell" + # + # You can mix it with +from+ method and do fun things like: + # + # str = "hello" + # str.from(0).to(-1) #=> "hello" + # str.from(1).to(-2) #=> "ell" def to(position) self[0..position] end + # Returns the first character. If a limit is supplied, returns a substring + # from the beginning of the string until it reaches the limit value. If the + # given limit is greater than or equal to the string length, returns self. + # + # str = "hello" + # str.first #=> "h" + # str.first(1) #=> "h" + # str.first(2) #=> "he" + # str.first(0) #=> "" + # str.first(6) #=> "hello" def first(limit = 1) if limit == 0 '' @@ -23,6 +84,16 @@ class String end end + # Returns the last character of the string. If a limit is supplied, returns a substring + # from the end of the string until it reaches the limit value (counting backwards). If + # the given limit is greater than or equal to the string length, returns self. + # + # str = "hello" + # str.last #=> "o" + # str.last(1) #=> "o" + # str.last(2) #=> "lo" + # str.last(0) #=> "" + # str.last(6) #=> "hello" def last(limit = 1) if limit == 0 '' |