ES6 Number.NaN
ES6 Number.NaN
该属性表示给定的值不是数字类型或者无法转换为合法的数字类型
语法
var val = Number.NaN;
例子
var dayOfMonth = 50; if (dayOfMonth < 1 || dayOfMonth > 31) { dayOfMonth = Number.NaN console.log("Day of Month must be between 1 and 31.") } else { console.log("day of month "+dayOfMonth) }
输出
Day of Month must be between 1 and 31.