javascript的number有四种特例: 设有一个数:number;如果它是下列情况,则右式成立: 有限数: isFinite(number) == true非数字: isNaN(number) == true正无穷大: number == Number.POSITIVE_INFINITY负无穷大: number == -Number.POSITIVE_INFINITY 转载于:https://www.cnblogs.com/vinstudio/archive/2010/03/30/1700637.html