在 JavaScript 中使用 function 转换温度时，如何消除 NaN 错误？

Question

I have been trying to make a JS Fahrenheit to Celsius converter, and for some reason whenever I input a number and that goes through the function, it spits back out a NaN where the Temperature is supposed to go.我一直在尝试制作一个 JS 华氏温度到摄氏温度的转换器，出于某种原因，每当我输入一个数字并经过 function 时，它会吐出一个NaN ，其中温度应该为 go。

Edit: Added in the "value" after the "ftemp" and "ctemp"编辑：在“ftemp”和“ctemp”之后的“值”中添加

Edit: I deleted the values in the ftemp and ctemp and instead tried to access them in the function itself just like two people answered, and it works fine now.编辑：我删除了 ftemp 和 ctemp 中的值，而是尝试在 function 本身中访问它们，就像两个人回答的那样，现在工作正常。

 function ftoc(ft) { c = ft * (9 / 5) + 32; return c; } function ctof(ct) { f = (c - 32) / (9 / 5); return f; } button1 = document.getElementById("ftempsubmit"); button2 = document.getElementById("ctempsubmit"); fvalue = document.getElementById("ftemp").value; cvalue = document.getElementById("ctemp").value; fpopup = document.getElementById("fpopup"); cpopup = document.getElementById("cpopup"); button1.onclick = function() { cpopup.value = ftoc(fvalue); }; button2.onclick = function() { fpopup.value = ctof(cvalue); };

 <input type="text" id="ftemp" placeholder="Enter F" /> <button id="ftempsubmit">Submit F</button> <br /> <br /> <input id="cpopup" /> <br /> <br /> <input type="text" id="ctemp" placeholder="Enter C" /> <button id="ctempsubmit">Sumbit C</button> <br /> <br /> <input id="fpopup" />

Answer 1

You are not sending the actual value of the inputs but rather the HTML element to your function which will throw NaN您不是将输入的实际value发送，而是将 HTML 元素发送到您的 function，这将抛出NaN

I have also change the type=text to type=number as you will using integer only for conversion .我还将type=text更改为type=number ，因为您将仅使用integer进行conversion 。

In your function ctof you are getting argument at ct but you are using c only when doing the calculation which mean it will throw an error of c not defined.在您的 function ctof中，您在ct处获得参数，但仅在进行计算时才使用c ，这意味着它将抛出c未定义的错误。

Live Demo:现场演示：

 function ftoc(ft) { var c = ft * (9 / 5) + 32; return c; } function ctof(ct) { var f = (ct - 32) / (9 / 5); return f; } button1 = document.getElementById("ftempsubmit"); button2 = document.getElementById("ctempsubmit"); fvalue = document.getElementById("ftemp"); cvalue = document.getElementById("ctemp"); fpopup = document.getElementById("fpopup"); cpopup = document.getElementById("cpopup"); button1.onclick = function() { cpopup.value = ftoc(+fvalue.value); }; button2.onclick = function() { fpopup.value = ctof(+cvalue.value); };

 <!DOCTYPE html> <html> <head></head> <body> <input type="number" id="ftemp" placeholder="Enter F" /> <button id="ftempsubmit">Submit F</button> <br /> <br /> <input id="cpopup" /> <br /> <br /> <input type="number" id="ctemp" placeholder="Enter C" /> <button id="ctempsubmit">Sumbit C</button> <br /> <br /> <input id="fpopup" /> <br /> <br /> <script> </script> </body> </html>

在 JavaScript 中使用 function 转换温度时，如何消除 NaN 错误？

问题描述

1 个解决方案

解决方案1
0 已采纳 2020-08-20 06:27:52

在 JavaScript 中使用 function 转换温度时，如何消除 NaN 错误？

问题描述

1 个解决方案

解决方案1 0 已采纳 2020-08-20 06:27:52

解决方案1
0 已采纳 2020-08-20 06:27:52