JavaScript NaN 属性

JavaScript NaN 属性

---

作者:w3pop.com 翻译/整理:w3pop.com 发布:2007-04-28 浏览:2361 :: ::

Definition and Usage
定义与用法

The NaN property indicates that a value is "Not a Number".
NaN属性表示一个值不是一个数字

Syntax
语法

NaN

---

Tips and Notes
提示：

Tip: Use the isNan() function to test a value to see if it is NaN.
提示：可以用isNan()方法测试一个值是否为NaN

---

Example
实例

In this example we will test two strings and find out if one of them is NaN:
在下面的例子中，我们将对两个值进行测试，找出非数字的值：

<script type="text/javascript">

var test1="300"

            var test2="你好！"

document.write(Number(test1)+ "<br />")

            document.write(Number(test2)+ "<br />")

document.write(isNaN(test1)+ "<br />")

            document.write(isNaN(test2))

</script>

The output of the code above will be:
输出结果为：

300

            NaN

            false

            true