Blocks, Procs and Lambdas
Below are some simple examples which will help highlight the differences between Blocks, Procs amd Lambdas.
Blocks are very common Ruby elements. For example;
Procedures or Procs for short are blocks that we can call again. If we call class on proc we will see that it is a proc object.
Notice if we call proc.call(2) we get 2, while proc.call is nil and proc.call(1,2,3) is 1 (the first number called, the other numbers get ignored).
Calling proc_check prints nothing.
Lambdas are variations on Procs. If we call class on lambda we will see that it is also a proc object.
One key difference is that if we call lambda.call(2) we get 2, while lambda.call and lambda.call(1,2,3) both raise ArgumentErrors.
Calling lambda_check prints 'I am a Lambda!!' because return triggers the puts right after the lam.call.
Resources
http://www.reactive.io/tips/2008/12/21/understanding-ruby-blocks-procs-and-lambdas/
http://rubylearning.com/satishtalim/ruby_blocks.html
http://awaxman11.github.io/blog/2013/08/05/what-is-the-difference-between-a-block/