输入返回NAN JavaScript

Question

heya再次：p我只是想知道是否有办法使Wallarea返回整数，因为目前它返回Nan：S任何帮助都将被赞赏：）亚伦〜

<form id="frm1" action="form_action.asp">
Number of walls: <input type="number" name="numberOfWallsInput" ><br>
Width of walls in meters: <input type="number" name="wallWidthInput" ><br>
Height of walls in meters: <input type="number" name="wallHeightInput" ><br>
</form>
<p>Number of walls: <p id="numberOfWallDiv"></p></p>
<p>Width of walls: <p id="wallWidthDiv"></p></p>
<p>Height of walls: <p id="wallHeightDiv"></p></p>
<p>Area of walls: <p id="wallAreaDiv"></p></p>

<button onclick="myFunction()">Try it</button>
<script>
function myFunction()
{
var numberOfWalls = document.getElementsByName("numberOfWallsInput")[0];
var wallWidth = document.getElementsByName("wallWidthInput")[0];
var wallHeight = document.getElementsByName("wallHeightInput")[0];
var wallArea = wallWidth*wallHeight;

document.getElementById("numberOfWallDiv").innerHTML = numberOfWalls.value;
document.getElementById("wallWidthDiv").innerHTML = wallWidth.value;
document.getElementById("wallHeightDiv").innerHTML = wallHeight.value;
document.getElementById("wallAreaDiv").innerHTML = wallArea;
}
</script>

Answer 1

您忘了拿到DOM元素的值。

替代

var wallArea = wallWidth*wallHeight;

var wallArea = wallWidth.value*wallHeight.value;

Answer 2

缺少计算值

var wallArea = parseInt(wallWidth.value, 10)*parseInt(wallHeight.value, 10);