What are the differences between lambda and proc in Ruby?

What are the differences between lambda and proc in Ruby?

In Ruby, both lambda and proc are used for creating anonymous functions, but they have key differences. A lambda checks the number of arguments passed to it, while a proc does not. Additionally, a lambda returns control to the calling method, whereas a proc returns from the method where it was defined.

Can you give me an example of each?

Sure! Here's a lambda example:

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

And a proc example:

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

What happens if I pass the wrong number of arguments to each?

If you pass the wrong number of arguments to a lambda, it will raise an ArgumentError. For example:

my_lambda.call(5, 10)  # Raises ArgumentError

In contrast, a proc will not raise an error and will simply ignore the extra arguments.

Are there any performance differences between them?

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