alias vs. alias_method.md

alias 和 alias_method 区别 ruby

1

class User

  def full_name
    puts "Johnnie Walker"
  end

  alias name full_name
end

User.new.name #=>Johnnie Walker

• 这两个例子中 alias 不需要逗号,还有冒号(或者双引号)

class User

  def full_name
    puts "Johnnie Walker"
  end

  alias_method :name, :full_name
end

User.new.name #=>Johnnie Walker

2

---

class User

  def full_name
    puts "Johnnie Walker"
  end

  def self.add_rename
    alias_method :name, :full_name
  end
end

class Developer < User
  def full_name
    puts "Geeky geek"
  end
  add_rename
end

Developer.new.name #=> 'Gekky geek'

• 这两个例子中可以看出作用域不同,alias是进入原类进行操作,而alias_method是查找当前类同名方法进行操作

class User

  def full_name
    puts "Johnnie Walker"
  end

  def self.add_rename
    alias :name :full_name
  end
end

class Developer < User
  def full_name
    puts "Geeky geek"
  end
  add_rename
end

Developer.new.name #=> 'Johnnie Walker'