“this"的 Ruby 等价物是什么?Java中的函数?

问题描述

在 Java 中有一个指向它的方法的this"函数.Ruby 中是否有等价物?例如，是否有:

In Java there is a "this" function that points to its method. Is there an equivalent in Ruby? For instance, is there:

def method
  this.method
end

推荐答案

相当于 self.这也是隐含的.所以self.first_name 和班级中的first_name 是一样的，除非你是在做作业.

The equivalent is self. It is also implict. So self.first_name is the same as first_name within the class unless you are making an assignment.

class Book
  attr_reader :first_name, :last_name

  def full_name
     # this is the same as self.first_name + ", " + self.last_name
    first_name + ", " + last_name
  end
end

在进行赋值时，您需要显式使用 self，因为 Ruby 无法知道您是在分配名为 first_name 的局部变量还是分配给 instance.first_name.

When making an assignment you need to use self explicitly since Ruby has no way of knowing if you are assigning a local variable called first_name or assigning to instance.first_name.

class Book
  def foo
    self.first_name = "Bar"
  end
end

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