What are some examples of using procs in Ruby?

What are some examples of using procs in Ruby?

In Ruby, a proc is an object that encapsulates a block of code. Here are a few examples:

1. Basic Proc Creation:

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

2. Using Procs with Methods:

   def execute_proc(proc)
     proc.call
   end
   my_proc = Proc.new { puts 'Hello from proc!' }
   execute_proc(my_proc)  # Outputs: Hello from proc!
   

3. Procs with Arguments:

   add = Proc.new { |a, b| a + b }
   puts add.call(2, 3)  # Outputs: 5
   

Would you like to see more examples or learn about lambdas?

Can you explain the difference between procs and lambdas?

Sure! The main differences between procs and lambdas in Ruby are:

1. Argument Handling:

   • Procs do not enforce the number of arguments. If you pass fewer arguments, it will assign nil to the missing ones.
   • Lambdas check the number of arguments and will raise an error if the count doesn't match.

2. Return Behavior:

   • A return statement in a proc will return from the method enclosing the proc.
   • A return in a lambda will only return from the lambda itself.

Would you like to see examples of these differences?

Yes, please provide examples of the differences.

Here are examples illustrating the differences:

1. Argument Handling:

   my_proc = Proc.new { |x| puts x }
   my_proc.call(1)  # Outputs: 1
   my_proc.call     # Outputs: 
   
   my_lambda = ->(x) { puts x }
   my_lambda.call(1)  # Outputs: 1
   my_lambda.call     # Raises ArgumentError
   

2. Return Behavior:

   def proc_example
     my_proc = Proc.new { return 'Returned from proc' }
     my_proc.call
     'This will not be reached'
   end
   puts proc_example  # Outputs: Returned from proc
   
   def lambda_example
     my_lambda = -> { return 'Returned from lambda' }
     my_lambda.call
     'This will be reached'
   end
   puts lambda_example  # Outputs: This will be reached
   

Let me know if you have more questions!