- %Q
用于替代双引号的字符串. 当你需要在字符串里放入很多引号时候, 可以直接用下面方法而不需要在引号前逐个添加反斜杠 (")
%Q(Joe said: “Frank said: “#{what_frank_said}””) => “Joe said: “Frank said: “Hello!”””
(…)也可用其他非数字字母的符号或成对的符号代替, 诸如[…], !…!, +…+,{…}, <…>等.
以下写法全部与上面等效:
%Q!Joe said: “Frank said: “#{what_frank_said}””! %Q[Joe said: “Frank said: “#{what_frank_said}””] %Q+Joe said: “Frank said: “#{what_frank_said}””+
除此之外还可省略Q写作:
%/Joe said: “Frank said: “#{what_frank_said}””/ => “Joe said: “Frank said: “Hello!”””
%q
与%Q类似, 但是表示的是单引号字符串
%q(Joe said: ‘Frank said: ‘#{what_frank_said} ‘ ‘) => “Joe said: ‘Frank said: ‘#{what_frank_said} ‘ ‘”
%W
语法近似于%Q, 用于表示其中元素被双引号括起的数组.
%W(#{foo} Bar Bar\ with\ space) => [“Foo”, “Bar”, “Bar with space”]
%w
用于表示其中元素被单引号括起的数组. 比较奇怪的是(斜杠空格)会被转化成(空格), 但是其他的内容不会.
%w(a b c\ d #e #{1}f) => [“a”, “b”, “c d”, “\#e”, “#{1}f”]
%x
使用`方法执行一段shell脚本并返回标准输出内容.
%x(echo foo:#{foo}) => “foo:Foo\n”
%r
语法近似于%Q, 用于正则表达式.
%r(/home/#{foo}) => “/\/home\/Foo/”
%s
用于表示symbol, 但是不会对其中表达式等内容进行转化
%s(foo) => :foo %s(foo bar) => :”foo bar” %s(#{foo} bar) => :”#{foo} bar”
%i
Ruby 2.0 之后引入的语法, 用于生成一个symbol数组
2.0.0p247 :014 > %i(a b c) => [:a, :b, :c]
