What are closures in Ruby and can you give me some examples?

What are closures in Ruby and can you give me some examples?

Closures in Ruby are blocks of code that can capture the surrounding context. For example, a closure can remember variables from its scope even after that scope has finished executing.

Can you show me a simple 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

In this example, make_counter returns a closure that increments count each time it's called.

What happens if I try to access count outside of the closure?

If you try to access count outside of the closure, you'll get an error because count is not in the scope of the outer context. Closures encapsulate their variables.