负无穷大

• Dividing a floating - point value by zero will result in either positive infinity , negative infinity , or not - a - number according to the rules of ieee 754 arithmetic
  根据ieee 754算法规则，用零除浮点值将产生正无穷大、负无穷大或非数字( nan ) 。
• Standard ieee floating point has other oddities that you need to be prepared for , such as positive and negative infinities , and negative zero as well as positive zero
  ） 。您还需要知道标准ieee浮点数的其他特殊定义，比如正无穷大和负无穷大，负零（还有正零） 。