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Start your free trialArjun Temurnikar
9,695 PointsWhat am I doing wrong?
Challenge: Call the run method on the benchmarker object and pass it two arguments. The first argument should be a string of the description. The second argument can be a block with any code you choose.
class SimpleBenchmarker
def run(description, &block)
start_time = Time.now
block.call
end_time = Time.now
elapsed = end_time - start_time
puts "\n#{description} results"
puts "Elapsed time: #{elapsed} seconds"
end
end
benchmarker = SimpleBenchmarker.new
benchmarker.run "Something" { puts "This is a block." }
I don't understand what I am doing wrong here.
1 Answer
Arjun Temurnikar
9,695 PointsI found out why I was wrong.
When the run method has only one argument like so:
Class Benchmarker
def run(&block)
# do something
end
end
then, this is valid ruby:
benchmarker.run { puts "This is block." }
But, when the method has 2 arguments like so:
Class Benchmarker
def run(description, &block)
# do something
end
end
then, one has to use the do...end syntax to pass the block like so:
benchmarker.run "This is a description." do
puts "This is block."
end
Namely, one cannot pass {} as an argument in a method ().
This:
run("fast", {puts "today"})
is invalid syntax.
That's why blocks are passed as &block
My mistake was that I assumed {}
and do...end
are ALWAYS interchangeable.
I guess this is an exception.
I am posting here so that it might be helpful to others.
Heather Stone
5,784 PointsHeather Stone
5,784 PointsThank you!
Dusty Longwell
6,981 PointsDusty Longwell
6,981 PointsVery helpful!! I was confused as to why it would not work also. I don't think the use of & was described very well in the video.