What are lambdas and procs in Ruby?

Can you explain the difference between a lambda and a proc in Ruby?

Sure! Both lambdas and procs are used to encapsulate blocks of code, but they have some key differences. Lambdas check the number of arguments passed, while procs do not. Additionally, lambdas return control to the calling method, whereas procs return from the method they were defined in.

Can you give me an example of how to use a lambda?

Of course! Here's a simple example:

my_lambda = ->(x) { x * 2 }
puts my_lambda.call(5)  # Output: 10

This lambda takes one argument and doubles it.

What about a proc? How is it different in usage?

Here's how you can define and use a proc:

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

Notice that you can call it without passing an argument, and it will still work.

Are there any performance differences between them?

Generally, lambdas are slightly faster than procs due to their stricter argument checking. However, the difference is usually negligible unless you're calling them in a performance-critical loop.