Onkeyup javascript 错误计算变化

Question

我尝试使用 javascripts 自动计算零钱，当我在支付中输入一些数字时，零钱输入将自动填充零钱

<!DOCTYPE html>
<html>
<body>


subtotal: <input type="number" id="subtotal" value="20000">
pay : <input type="number" id="dibayar" onkeyup="kembalian()">

<p>change: <span id="demo"></span></p>

<script>
function kembalian() {
        var x = document.getElementById("subtotal").value;
        var y = document.getElementById("dibayar").value;
        var awe = x - y;
        console.log(awe);
document.getElementById("kembalian").innerHTML = awe;
        }

</script>

</body>
</html>

Answer 1

您需要将其插入demo id

function kembalian() {
  var x = document.getElementById("subtotal").value;
  var y = document.getElementById("dibayar").value;
  var awe = x - y;
  console.log(awe);
  document.getElementById("demo").innerHTML = awe;
}

subtotal: <input type="number" id="subtotal" value="20000"> pay : <input type="number" id="dibayar" onkeyup="kembalian()">

<p>change: <span id="demo"></span></p>

Answer 2

首先，如果您想在 "change" 中设置新值，您应该更改

document.getElementById("kembalian").innerHTML = awe;

至

document.getElementById("demo").innerHTML = awe;

如果还是不行，您也可以尝试将 onkeyup 更改为 onchange。

Answer 3

检查ID！它应该是： document.getElementById("demo").innerHTML = 敬畏;

Onkeyup javascript 错误计算变化

Onkeyup javascript error to calculate change

html

javascript

onkeyup