luckydev

How to declare a method:

- (returntype)nameofTheMethodParam:(paramtype)paramname andAnotherParam:(paramtype)paramname;
+ (returntype)nameofTheMethodParam:(paramtype)paramname andAnotherParam:(paramtype)paramname;

Not like these:

-(returntype)nameofTheMethodParam:(paramtype)paramname andAnotherParam:(paramtype)paramname;

-(returntype) nameofTheMethodParam:(paramtype)paramname andAnotherParam:(paramtype)paramname;

luckydev

#define UIColorFromRGB(rgbValue) [UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 green:((float)((rgbValue & 0xFF00) >> 8))/255.0 blue:((float)(rgbValue & 0xFF))/255.0 alpha:1.0]

luckydev

irb(main):007:0> class Person
irb(main):008:1> attr_accessor :name,:email
irb(main):009:1> end
=> nil
irb(main):010:0> p = Person.new
=> #<Person:0x007fa40a038378>
irb(main):011:0> p.name
=> nil
irb(main):012:0> p.email
=> nil

luckydev

#all these will render guests/new.html.erb template 
#calling from an action in ActivitiesConctoller, for example.

render "guests/new"
render "guests/new.html.erb"
render :template => "guests/new"
render :template => "guests/new.html.erb"

luckydev

# SeniorDev, AwesomeDev, NoviceDev

class SeniorDev
  def do_some_old_stuff
    puts "This is a piece of cake"
  end

  def method_missing(name, *args)
    puts "Err.. What? #{name}??..  THAT IS IMPOSSIBLE! Leave me alone."
  end

luckydev

my_super_code = lambda { |a,b| return a+b; }
puts my_super_code.call(1,2,5)

#=> ArgumentError: wrong number of arguments (3 for 2)

luckydev

def my_awesome_method
  ret = lambda { return "This is returned from Lambda" }
  ret.call
  "This line will run"
end

puts my_awesome_method

# => "This is returned from Lambda"
# => "This line will run"

luckydev

ruby-1.9.2-p180 :001 >   Account.find(34)
ActiveRecord::RecordNotFound: Couldn't find Account with ID=34
	from /Users/lakshman/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.5/lib/active_record/relation/finder_methods.rb:296:in `find_one'
	from /Users/lakshman/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-
ruby-1.9.2-p180 :002 > Account.where(:id => 34).first
 => nil 
ruby-1.9.2-p180 :003 > Account.where(:id => 34)
 => []

luckydev

$ bundle install
Fetching source index for http://rubygems.org/
Installing rake (0.9.2) 
Installing abstract (1.0.0) 
Installing activesupport (3.0.5) 
Installing builder (2.1.2) 
Installing i18n (0.6.0) 
Installing activemodel (3.0.5) 
Installing erubis (2.6.6) 
Installing rack (1.2.3) 

luckydev

class MyClass

  def my_instance_method
    puts "this is an instance method"
  end

  #self here is MyClass
  class << self
    def count_objects
      "counting objects..DONE"