What is the difference between closures and procs in Ruby?

What is the difference between closures and procs in Ruby?

In Ruby, a closure is a function that captures the lexical scope in which it was defined, while a proc is an object that encapsulates a block of code.

Can you give me an example of a closure in Ruby?

Sure! Here's a simple example:

def make_counter
  count = 0
  -> { count += 1 }
end

counter = make_counter
puts counter.call  # Outputs: 1
puts counter.call  # Outputs: 2

And how does that differ from a proc?

A proc can be created using Proc.new or the proc method. Unlike closures, procs do not have their own scope; they use the scope of where they were defined. Here's an example:

my_proc = Proc.new { |x| x * 2 }
puts my_proc.call(5)  # Outputs: 10

Are there any performance differences between using closures and procs?

Yes, closures can be more efficient in certain scenarios because they maintain their own context, while procs may introduce overhead due to their object nature.