我试图从html中获取两个数字，并使用javascript返回两者的和，但是num1和num2包含htmlinputtement？?
html格式：
<head>
<script type ="text/javascript" src="functions.js"></script>
</head>
<body>
Value 1: <input type="text" id="tb1" name="tb1"><br/>
Value 2: <input type="text" id="tb2" name="tb2"><br/>
Result: <input type="text" id="tb3" name="tb3"><br/>
<button onclick="validateForm()" Type="button" id="b1" name="b1">Go</button>
</body>
javascript代码：
function validateForm() {
var x = document.getElementById("tb1");
var y = document.getElementById("tb2");
if (x == null || x == "" || y == null || y == "")
{
alert("Value cannot be empty");
return false;
}
else {
//myAdd(x,y);
alert(x + y);
var num1 = parseFloat(x);
var num2 = parseFloat(y);
var total = num1 + num2;
document.getElementById("tb3").innerHTML = total;
}
}
最佳答案
您不是从这两个输入解析和添加values，而是从objects本身。因为您的if语句块将never run，因为您正在将object与null进行比较。此外，您不能设置innerHTML的input，必须使用.value。请检查下面的代码片段
parseFloat(x) //you must parseFloat(x.value),
document.getElementById("tb3").value = total; //you have to use .value instead of .innerHTML with input
function validateForm() {
var x = document.getElementById("tb1").value;
var y = document.getElementById("tb2").value;
if (x == null || x === "" || y == null || y === "") {
alert("Value cannot be empty");
return false;
} else {
//myAdd(x,y);
var num1 = parseFloat(x);
var num2 = parseFloat(y);
var total = num1 + num2;
document.getElementById("tb3").value = total;
}
}Value 1:
<input type="text" id="tb1" name="tb1">
<br/>Value 2:
<input type="text" id="tb2" name="tb2">
<br/>Result:
<input type="text" id="tb3" name="tb3">
<br/>
<button onclick="validateForm()" Type="button" id="b1" name="b1">Go</button>