我正在用HTML创建一个网页,其中包含javascript和带有提交按钮的小表单,该按钮调用了整个javascript代码的功能。
这应该作为BMR +维护热量计算器。使用以下公式显示:
http://www.bmi-calculator.net/bmr-calculator/bmr-formula.php
http://www.bmi-calculator.net/bmr-calculator/harris-benedict-equation/
男性公制BMR = 66 +(13.7 x千克重量)+(5 x高度厘米)-(6.8 x年龄单位)
女性公制BMR = 655 +(9.6 x公斤重量)+(1.8 x高度厘米)-(4.7 x年龄单位)
然后要发现一些日常维护热量需求(保持相同的体重),需要根据活动水平进行乘数计算。正是在创建这些IF语句时,我才开始遇到这些问题。
问题:当我单击提交时,什么都没有发生。它曾经将用户发送到显示文档的新页面。编写文本,但是现在,它什么也不做。
我认为这是一个相当简单的问题,但我对javascript还是陌生的,因此将不胜感激,非常感谢!
<html>
<head>
<title>BMR Calculator</title>
</head>
<body>
<h1> BMR Calculator and Daily Maintenance Calorie Calculator </h1>
<script type="text/javascript" language="javascript">
function Calculate() {
var gender = document.getElementById("gender").value;
var weight = document.getElementById("weight").value;
var height = document.getElementById("height").value;
var age = document.getElementById("age").value;
var result = document.getElementById("result").value;
var MaintenanceCalories = document.getElementById("MaintenanceCalories").value;
var activitylevel = document.getElementById("activitylevel").value;
if(gender=="male")
//English-BMR = 66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) - ( 6.8 x age in year )
//Metric-BMR = 66 + ( 13.7 x weight in kilos ) + ( 5 x height in cm ) - ( 6.8 x age in years )
{
val1 = 13.7 * weight;
val2 = 5 * height;
val3 = 6.8 * age;
result = 66 + val1 + val2 - val3;
val4 = activitylevel;
}
else if (gender=="female")
//English-Women: BMR = 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) - ( 4.7 x age in years)
//Women: BMR = 655 + ( 9.6 x weight in kilos ) + ( 1.8 x height in cm ) - ( 4.7 x age in years )
{
val1 = 9.6 * weight;
val2 = 1.8 * height;
val3 = 4.7 * age;
result = 655 + val1 + val2 - val3;
val4 = activitylevel;
}
if(val4=="l")
{
MaintenanceCalories = result * 1.2;
}
if(val4=="lm")
{
MaintenanceCalories = result * 1.375;
}
if(val4=="m")
{
MaintenanceCalories = result * 1.55;
}
if(val4=="mh")
{
MaintenanceCalories = result * 1.725;
}
else if(val4=="h")
{
MaintenanceCalories = result * 1.9;
}
document.write ('Your BMR is: ' + result.toFixed(2) + '. Your Maintenance Calories are: ' + MaintenanceCalories.toFixed(2));
}
</script>
<form action="#">
Gender : <select id="gender">
<option value="male">Male</option>
<option value="female">Female</option>
</select><br/>
Weight (kg.) : <input type="text" id="weight" /><br />
Height (cm): <input type="text" id="height" /><br />
Age : <input type="text" id="age" /><br />
Current Activity Level: <select id="activitylevel">
<option value="l">Sedentary (Little or No Exercise)</option>
<option value="lm">Lightly Active (Light Exercise/Sports 1-3 Days Per Week)</option>
<option value="m">Moderately Active (Moderate Exercise/Sports 3-5 Days Per Week)</option>
<option value="mh">Very Active (Hard Exercise/Sports 6-7 days Per Week)</option>
<option value="h">Extra Active (Very Intense Exercise/Sports and Physical Job Daily)</option>
</select>
</br>
</br>
</fieldset>
<input type="button" value="Submit" onclick="Calculate()"/>
</form>
最佳答案
你的问题就在网上document.write ('Your BMR is: ' + result.toFixed(2)'. Your Maintenance Calories are: ' + MaintenanceCalories.toFixed(2));
您缺少+
的地方:
document.write ('Your BMR is: ' + result.toFixed(2) + '. Your Maintenance Calories are: ' + MaintenanceCalories.toFixed(2));
另外,在给定的示例中,您缺少一些使脚本工作所需的html元素。
#result
和#MaintenanceCalories
我像这样添加了它们,效果很好:
<div id="result"></div>
<div id="MaintenanceCalories"></div>
另一方面,如果您使用空字符串初始化这些值(也无需再添加html标记)也可以:
var result = '';
var MaintenanceCalories = '';
此外,为了将表单保留在页面上,可以在表单的结束标记后添加一个div,可以在其中显示结果:
<div id="results"></div>
和JavaScript,位于
Calculate()
函数的末尾:results.innerHTML ='Your BMR is: ' + result.toFixed(2) + '. Your Maintenance Calories are: ' + MaintenanceCalories.toFixed(2);