Question

proc = Proc.new do |name|
  puts "Thank you #{name}!"
end
def thank
  yield
end

proc.call # output nothing, just fine
proc.call('God') # => Thank you God!

thank &proc # output nothing, too. Fine;
thank &proc('God') # Error!
thank &proc.call('God') # Error!
thank proc.call('God') # Error!
# So, what should I do if I have to pass the 'God' to the proc and use the 'thank' method at the same time ?

谢谢：）

Answer 1

我认为最好的方法是：

def thank name
  yield name if block_given?
end

Answer 2

def thank(arg, &block)
  yield arg
end

proc = Proc.new do|name|
   puts "Thank you #{name}"
end

然后你可以这样做：

thank("God", &proc)

Answer 3

与Nada提出的不同的方式（它是相同的，只是不同的语法）：

proc = Proc.new do |name|
    puts "thank you #{name}"
end

def thank(proc_argument, name)
    proc_argument.call(name)
end

thank(proc, "for the music") #=> "thank you for the music"
thank(proc, "for the songs you're singing") #=> "thank you for the songs you're singing"

它有效，但我不喜欢它。然而，它将帮助读者了解如何使用过程和块。

如何通过方法调用参数传递给proc？

3 个答案: