Returns the value in the database associated with the given key string.
If a block is provided, the block will be called when there is no value associated with the given key. The key will be passed in as an argument to the block.
If no block is provided and no value is associated with the given key, then an IndexError will be raised.
Iterates over each key-value pair in the database.
If no block is given, returns an Enumerator.
iterates over the list of Addrinfo objects obtained by Addrinfo.getaddrinfo.
Addrinfo.foreach(nil, 80) {|x| p x } #=> #<Addrinfo: 127.0.0.1:80 TCP (:80)> # #<Addrinfo: 127.0.0.1:80 UDP (:80)> # #<Addrinfo: [::1]:80 TCP (:80)> # #<Addrinfo: [::1]:80 UDP (:80)>
See IO#each.
This is a deprecated alias for each_char.
Returns the character position of the scan pointer. In the ‘reset’ position, this value is zero. In the ‘terminated’ position (i.e. the string is exhausted), this value is the size of the string.
In short, it’s a 0-based index into the string.
s = StringScanner.new("abcädeföghi") s.charpos # -> 0 s.scan_until(/ä/) # -> "abcä" s.pos # -> 5 s.charpos # -> 4
Tests whether the given pattern is matched from the current scan pointer. Returns the length of the match, or nil. The scan pointer is not advanced.
s = StringScanner.new('test string') p s.match?(/\w+/) # -> 4 p s.match?(/\w+/) # -> 4 p s.match?(/\s+/) # -> nil
This returns the value that scan would return, without advancing the scan pointer. The match register is affected, though.
s = StringScanner.new("Fri Dec 12 1975 14:39") s.check /Fri/ # -> "Fri" s.pos # -> 0 s.matched # -> "Fri" s.check /12/ # -> nil s.matched # -> nil
Mnemonic: it “checks” to see whether a scan will return a value.
Scans one character and returns it. This method is multibyte character sensitive.
s = StringScanner.new("ab") s.getch # => "a" s.getch # => "b" s.getch # => nil $KCODE = 'EUC' s = StringScanner.new("\244\242") s.getch # => "\244\242" # Japanese hira-kana "A" in EUC-JP s.getch # => nil
Returns true iff the last match was successful.
s = StringScanner.new('test string') s.match?(/\w+/) # => 4 s.matched? # => true s.match?(/\d+/) # => nil s.matched? # => false
Returns the last matched string.
s = StringScanner.new('test string') s.match?(/\w+/) # -> 4 s.matched # -> "test"
Iterates over each item of OLE collection which has IEnumVARIANT interface.
excel = WIN32OLE.new('Excel.Application') book = excel.workbooks.add sheets = book.worksheets(1) cells = sheets.cells("A1:A5") cells.each do |cell| cell.value = 10 end
Returns a value from the hash for the given key. If the key can’t be found, there are several options: With no other arguments, it will raise a KeyError exception; if default is given, then that will be returned; if the optional code block is specified, then that will be run and its result returned.
h = { "a" => 100, "b" => 200 } h.fetch("a") #=> 100 h.fetch("z", "go fish") #=> "go fish" h.fetch("z") { |el| "go fish, #{el}"} #=> "go fish, z"
The following example shows that an exception is raised if the key is not found and a default value is not supplied.
h = { "a" => 100, "b" => 200 } h.fetch("z")
produces:
prog.rb:2:in `fetch': key not found (KeyError) from prog.rb:2
Calls block once for each key in hsh, passing the key-value pair as parameters.
If no block is given, an enumerator is returned instead.
h = { "a" => 100, "b" => 200 } h.each {|key, value| puts "#{key} is #{value}" }
produces:
a is 100 b is 200
Retrieves the environment variable name.
If the given name does not exist and neither default nor a block a provided an KeyError is raised. If a block is given it is called with the missing name to provide a value. If a default value is given it will be returned when no block is given.
Yields each environment variable name and value.
If no block is given an Enumerator is returned.
Returns an enumerator which iterates over each line (separated by sep, which defaults to your platform’s newline character) of each file in ARGV. If a block is supplied, each line in turn will be yielded to the block, otherwise an enumerator is returned. The optional limit argument is an Integer specifying the maximum length of each line; longer lines will be split according to this limit.
This method allows you to treat the files supplied on the command line as a single file consisting of the concatenation of each named file. After the last line of the first file has been returned, the first line of the second file is returned. The ARGF.filename and ARGF.lineno methods can be used to determine the filename of the current line and line number of the whole input, respectively.
For example, the following code prints out each line of each named file prefixed with its line number, displaying the filename once per file:
ARGF.each_line do |line| puts ARGF.filename if ARGF.file.lineno == 1 puts "#{ARGF.file.lineno}: #{line}" end
While the following code prints only the first file’s name at first, and the contents with line number counted through all named files.
ARGF.each_line do |line| puts ARGF.filename if ARGF.lineno == 1 puts "#{ARGF.lineno}: #{line}" end
This is a deprecated alias for each_char.