String objects are instances of the String class, and have their own methods.
"abc123".length # 6 They are not immutable by default, but you can make them immutable via the freeze method. Strings are not lists of characters, and accessing a single element returns the ASCII value for the byte, not the character.
str = 'ABC' puts str[0] # 65 puts ?A # 65 puts str[0,1] # "A" puts str[0].chr # "A" The numeric approach facilitates languages having multi-byte characters, such as Japanese. Iterating over a string will by default deliver one line at a time. You can also iterate over one byte at a time, but remember that you might need to convert bytes to characters.
"abc".each_byte do |b| # convert to character before print b.chr.upcase # using string method end # "ABC" There is no equivalent to Python's r"" raw string or the u"" Unicode string. Using double quotes has a different effect from using single quotes because they allow interpolation. Backticks are also different in Ruby, treating their contents as a shell command and evaluating them on the spot. Regular expressions likewise have special default quoting (forward slashes):
'a do-nothing string' # escape single quotes and backslashes "This is\ntwo lines." # Notice - not like single quotes `ls -l` # Notice - not repr() /^(.*?)=(.*?)$/ # regex literal Ruby has special quoting constructs so you can specify other delimiters for these; refer to documentation of %q, %Q, %x, and %r. Ruby allows for string interpolation in addition to the familiar % formatting.
x = 5 puts "I have %s apples" % (x-2) puts "I have #{ x-2} apples." Ruby's string interpolator, #{}, can be used inside double quote constructs, regexes, and shell strings. You can use "here-docs" in place of Python's triple quotes.
heredoc = <<MARKER Now I can type "freely" Date: #{ Time.now} MARKER Here-docs also come in other forms supporting single- and shell-quoted strings, as well as indented here-docs.
def whois(domain=nil) print <<-`SHELL` whois #{ domain||gets} @networksolutions.com SHELL end |