java中isnan函数
Prerequisite:NaN property in JavaScript
先决条件：JavaScript中的NaN属性
isNaN()函数 (isNaN() function)
isNaN() functionis a predefined global function in JavaScript and it is used to check whether a given value is an illegible number or not. If the given value is an illegal number - it returns true and if the given value is a legal number – it returns false.
isNaN()函数是JavaScript中预定义的全局函数，用于检查给定值是否为难以辨认的数字。 如果给定值是非法数字-则返回true ；如果给定值是合法数字-则返回false 。
Example:
例：
<html><head><title>JavaScipt Example</title></head><body><script>var num1 = 10;var num2 = parseInt("Hello");//printing the valuesdocument.write("num1: " + num1 + "<br>");document.write("num2: " + num2 + "<br>");//checking illegal value using isNaN() functionif(isNaN(num1))document.write("num1 is an illegal number <br>");elsedocument.write("num1 is a legal number <br>");if(isNaN(num2))document.write("num2 is an illegal number <br>");elsedocument.write("num2 is a legal number <br>");</script></body></html>
Output
输出量
num1: 10num2: NaNnum1 is a legal number num2 is an illegal number
翻译自: /code-snippets/isNaN-function-with-example-in-javascript.aspx
java中isnan函数
