JavaScript计算返回NaN作为结果 [英] JavaScript calculations return NaN as result
问题描述
我正在开发一个带有日期并显示日期的html页面.我正在使用一个称为Zeller全等的公式.但是在JavaScript中,该公式返回结果"NaN".我用谷歌搜索了这个问题.无法找出解决方案. 这是采用值的html.
I am developing a html page that takes date and displays day. I am using a formula called Zeller's congruence. But in JavaScript the formula returns the Result "NaN". I googled the problem. Couldn't figure out the solution. Here is the html that takes values.
<form method="post">
<br/>
day:<input id="dd" name="dd" type="text"/><br/>
month:<input id="mm" name="mm" type="text"/><br/>
year:<input id="yy" name="yy" type="text"/><br/>
<input type="submit" value="go" onclick="day()"/><br/>
</form>
这是一段返回NaN的JavaScript公式.
Here is the piece of JavaScript formula thats returning NaN.
function day() {
var d=document.getElementById("dd").value;
var m=document.getElementById("mm").value;
var y=document.getElementById("yy").value;
var h=(d+(((m+1)*26)/10)+y+(y/4)+6*(y/100)+(y/400))%7;//returns NaN
var d2=((h+5)%7); code continues..
请帮助我.
先谢谢了.
推荐答案
在某些情况下,公式中的+
符号将进行字符串连接而不是sum,就像在JavaScript "1" + 1 === "11"
中那样.您需要使用parseInt
或parseFloat
函数将字符串中的值(从表单字段返回)转换为数字:
In some cases +
signs in your formula will do string concatenation instead of sum, as in JavaScript "1" + 1 === "11"
. You need to convert your values from strings (as returned from form fields) to numbers with parseInt
or parseFloat
functions:
var d = parseInt(document.getElementById("dd").value, 10);
或支持浮点数(如果需要):
or to support float numbers (if required):
var d = parseFloat(document.getElementById("dd").value);
或Number(v)
的快捷方式:
var d = +document.getElementById("dd").value;
这篇关于JavaScript计算返回NaN作为结果的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!