cheat sheets.

# Use single quotes \' to create a literal string. 
  # Inside a quoted string #{foobar}, \, ... is not interpreted.
  %q = single quoted 
  # e.g. 
  %q{ 'single quoted text' doesn't need to be escaped} =>  " 'single quoted
  text' doesn't need to be escaped"

  %Q = double quoted
  # e.g. %Q{ "doublee quoted text" doesn't need to be escaped}

  # Can replace curly braces with any other character, like a dot "."
  %q = single quoted
  # e.g.
  %q. 'single quoted text' doesn't need to be escaped. =>  " 'single quoted
  text' doesn't need to be escaped"

  # here document
  mystring = <<EOS
  this is a 
  mulitword 
  string
  EOS
  
  # Most operations don't change the orginal string.
  # Unless the bang \! is used or the method implies it, replace method.

  "a" + "b" => "ab"
  "a" << "b"  => "ab"
  b = "some string"
  "a#{b}" =>  "asome string" 
  "%d some text more text" % 33 => "33 some text more text" 
  "%d some text more text" % [55]  => "55 some text more text" 
  "some int %d some float %f" % [55, 44.7] =>  "some int %d some float %f" %
  [55, 44.7]
  # Massaging strings
  # Default will create a new string. For in-place changes add bang ! to method
  name

  capitilize	"tom".captilize => "Tom"
  upcase	"tom".upcase => "TOM"
  downcase	"TOM".downcase => "tom"
  swapcase	"tom".swapcase = "TOM"
  strip		 "  lose the outer spaces  ".strip => "lose the outer spaces"
  rstrip	 "  lose the right spaces   ".rstrip =>  "  lose the outer spaces" 
  lstrip	 " lose the left spaces    ".lstrip =>  "lose the outer spaces  " 
  chop		 "remove the last character".chop => "remove the last characte"
  chomp		 "remove trailing newline\n".chomp =>  "remove the the trailing
  newline"
  reverse	 " gnirts eht esrever".reverse => "reverse the string"

  # Getting character
  "foobar"[3] => 98 # ascii number for 'b'
  "foobar"[3].chr => "b" 
  "foobar"[3,2] => "ba"
  "foobar"[-2].chr => "a"

  # Getting Substrings
  "This is a string"[5, 4] => "is a"
  "foo bar baz"[/foo (\w+) baz/, 1]  => "bar"


  # Replacement
  foo = "bar"
  foo.replace "hush" => "hush"
  foo = "This is a string"
  foo[5, 4] => "is a"
  "Some string with  whitespace\n and\t\tlines".gsub(/\s+/,'_') =>
  "Some_string_with_whitespace_and_lines"
  
  # Equality
  "a" == "a" => true
  # they are not the place in memory. different obj ids
  "a".equal? "a" =>  false

  # Comparision
  <=> spaceship operator, return -1, 0, 1 for less than, equal to, greater than