How to store ruby code blocks

ruby block proc
user1241335 picture user1241335 · Oct 7, 2012 · Viewed 10.4k times · Source

I want to store a "code block" in a variable to be reused, something like:

block = do
|test| puts test
end

3.upto(8) block

Can someone show me what am I doing so obviously wrong? (Or if it's just impossible)

Answer

stephenmurdoch picture stephenmurdoch · Oct 7, 2012

There are many ways to do this in Ruby, one of which is to use a Proc:

foo = Proc.new do |test|
  puts test
end

3.upto(8) { foo.call("hello world") }

Read more about Procs:

Update, the above method could be rewritten as follows:

# using lower-case **proc** syntax, all on one line
foo = proc { |test| puts test }
3.upto(8) { foo.call("hello world") }

# using lambda, just switch the method name from proc to lambda
bar = lambda { |test| puts test }
3.upto(8) { bar.call("hello world") }

They're basically very similar methods, with subtle differences.

And finally, there are probably more elegant ways to do what I've outlined, be good to hear from anyone with a better way. Hope this helps.

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