两个文本字段的总和 - javascript
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Sum of two textfields - javascript
提问by Michiel
I found [this][1], rather difficult, javascript example online and I've implemented it with success in my website.
我在网上找到了 [this][1]，相当困难的 javascript 示例，并且我已经在我的网站上成功实现了它。
However, I would like to get the result of, in this case, the two subtotals in one new text-field.
但是，在这种情况下，我想获得一个新文本字段中的两个小计的结果。
The traditional getElementbyIdand total.value=totaldidn't work out.
传统的getElementbyId并total.value=total没有奏效。
EDIT
编辑
function doMath()
{
// Capture the entered values of two input boxes
var twogiga = document.getElementById('twogig').value;
var fourgiga = document.getElementById('fourgig').value;
// Add them together and display
var sum = parseInt(twogiga) + parseInt(fourgiga);
document.getElementById('total').value = parseInt(sum);
}
This is the javascript I use. But for some reason, when I have just one value (twogig), the totalis set as NaN. What is wrong with my script?
这是我使用的javascript。但出于某种原因，当我只有一个值 ( twogig) 时，将total设置为 NaN。我的脚本有什么问题？
回答by John
Well, if you have assigned ID's to text inputs, for example: <input type="text" id="my_input" />, then you can call it with document.getElementById('my_input').value.
好吧，如果您已将 ID 分配给文本输入，例如：<input type="text" id="my_input" />，那么您可以使用 document.getElementById('my_input').value 调用它。
So:
所以：
<input type="text" id="my_input1" />
<input type="text" id="my_input2" />
<input type="button" value="Add Them Together" onclick="doMath();" />
<script type="text/javascript">
function doMath()
{
// Capture the entered values of two input boxes
var my_input1 = document.getElementById('my_input1').value;
var my_input2 = document.getElementById('my_input2').value;
// Add them together and display
var sum = parseInt(my_input1) + parseInt(my_input2);
document.write(sum);
}
</script>
Naturally, that is a very basic script, it doesn't check to make sure the entered values are numbers. We have to convert the fields into integers, otherwise they'll be strings (so 2+2 would equal 22). When the button is clicked, the function is called, which makes a variable for each input box, converts them to ints, adds them, and outputs our sum.
当然，这是一个非常基本的脚本，它不会检查以确保输入的值是数字。我们必须将字段转换为整数，否则它们将是字符串（因此 2+2 将等于 22）。当按钮被点击时，该函数被调用，它为每个输入框创建一个变量，将它们转换为整数，将它们相加，并输出我们的总和。
回答by SuperKael
Replace:
代替：
document.getElementById('total').value = parseInt(sum);
With:
和：
document.getElementById('total').value = sum;
You have already done all the int-parsing you need to do.
您已经完成了所有需要进行的 int 解析。
回答by gauravbhai daxini
$("#value1, #value2").on('focusout', function() {
var value2 = parseInt($("#value2").val()) > 0 ? parseInt($("#value2").val()) : 0;
var value1 = parseInt($("#value1").val()) > 0 ? parseInt($("#value1").val()) : 0
var sumOfValues = value1 + value2;
console.log('Your sum is ' + sumOfValues);
});<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="text" class="input" id="value1">
<input type="text" class="input" id="value2">