Ruby {…}是什么意思？

例如，在《为什么》的《辛酸指南》中的以下代码中：

def wipe_mutterings_from( sentence ) 
     unless sentence.respond_to? :include?
         raise ArgumentError, "cannot wipe mutterings from a #{ sentence.class }"
     end
     while sentence.include? '('
         open = sentence.index( '(' )
         close = sentence.index( ')', open )
         sentence[open..close] = '' if close
     end
end

“#{}”

在Ruby字符串插值中的意思。有关太多的答案，请参阅。

#{}

用于Ruby插值。在这个例子中

这将在消息中引发ArgumentError

无法从文件中删除喃喃自语

---

在Ruby双引号字符串中，这是一个有用的读取-

，其中包括字符串文本，如

s=“…”

和

s=%Q{…}

和

s=字符串插值意味着变量/表达式的内容被放入该位置的嵌入字符串中。您可能需要添加括号内的间距不相关<代码>“我有{I}只猫”

也有效。@NielsB。考虑到你可以有多行，而且有一些例子显示没有空格，你是否同意编辑明确了这一点？是的，现在已经非常彻底了。

i = 42
s = "I have #{ i } cats!"
#=> "I have 42 cats!"

i = 42
s= "I have " + i.to_s + " cats!"
#=> "I have 42 cats!"

"I've seen #{
  i = 10
  5.times{ i+=1 }
  i*2
} weasels in my life"
#=> "I've seen 30 weasels in my life"

[4,3,2,1,"no"].each do |legs|
  puts "The frog has #{legs} leg#{:s if legs!=1}"
end
#=> The frog has 4 legs
#=> The frog has 3 legs
#=> The frog has 2 legs
#=> The frog has 1 leg
#=> The frog has no legs

s = "The answer is #{6*7}" #=> "The answer is 42"
s = 'The answer is #{6*7}' #=> "The answer is #{6*7}"

s = %Q[The answer is #{ 6*7 }] #=> "The answer is 42"
s = %q[The answer is #{ 6*7 }] #=> "The answer is #{6*7}"

s = <<ENDSTRING
The answer is #{6*7}
ENDSTRING
#=> "The answer is 42\n"

s = <<'ENDSTRING'
The answer is #{6*7}
ENDSTRING
#=> "The answer is #{6*7}\n"

@cats = 17
s1 = "There are #{@cats} cats" #=> "There are 17 cats"
s2 = "There are #@cats cats"   #=> "There are 17 cats"