ruby send method

Hi all

I am started using the method named "send".

We can use this to call the method using object.

class User

def say_hello
"Hello"
end

end

u = User.new
puts u.send(:say_hello)

Here the class "User" is having the method called say_hello. We can create an object for the user class and call the method using the method "send"

Cheers,
vadivelan

ruby extend method

Hi all,

I have seen the method named "extend" used in a line of code in Plugin. Then i started searching for the use of method "extend". And i found the following

consider the example

module Friend
def say_hello
"hello am inside module"
end
end

class Person
def say_hello
"hello am inside class"
end
end

p = Person.new
puts p.say_hello #=> hello am inside class

p.extend(Friend) #=> include all the instance method from Module "Friend"
puts p.say_hello #=> hello am inside module


So the extend method is used to include the Module.
Without this we cannot call the method inside the module using the Person object. Even if i added include the module in the class, it wont calls the module method. The instance method inside the class gets called for the object(Person class).

Use of Proc & proc

Hi

I have used "proc" to run/block validation in model. But now i learned something more about proc.
In ruby, "Proc"(procedure) refers to the block of code, we can reuse it. Block of code assigned to the object.

"Proc" => Starts with capital letter refers to (class name)
"proc" => Refers to the proc object

We can use both the keywords to create a proc by defining any block to them.

below sample code to create a proc and call that proc to execute the block of code

accepts_any_arg = Proc.new{ |a,b,c|
puts "#{a} #{b} #{c}"
}
accepts_any_arg.call(1)
result: 1
accepts_any_arg.call(1,2)
result: 1 2
It just neglects the number of arguments required or passing to that proc, it is working without any argument error. It assigns nil value to arguments which are not passed.


throws_args_error = proc{ |a,b,c|
puts "#{a} #{b} #{c}"
}
throws_args_error.call(1,2,3)
result: 1 2 3
throws_args_error.call(1)
result: Throws "ArgumentError"
it is checking the number of arguments


Thanks,
Vadivelan