12、Ruby 赋值与运算符详解

Ruby 赋值与运算符详解

1. 赋值相关概念

赋值操作在 Ruby 编程中是基础且重要的部分，不同类型的赋值有着不同的规则和用途。

1.1 方法与变量的混淆示例

class Ambiguous
  def x; 1; end # A method named "x". Always returns 1
  def test
    puts x      # No variable has been seen; refers to method above: prints 1
    # The line below is never evaluated, because of the "if false" clause. But
    # the parser sees it and treats x as a variable for the rest of the method.
    x = 0 if false
    puts x    # x is a variable, but has never been assigned to: prints nil
    x = 2     # This assignment does get evaluated
    puts x    # So now this line prints 2
  end
end

在这个示例中， x 最初被当作方法调用，直到解析器看到 x = 0 if false 这行代码，即使这行代码不会被执行，但解析器会将后续的