如何求和2个数字
我需要对两个数字求和，但它给了我 NaN。我怎样才能让它工作？我已经尝试过 parseInt 但同样的事情。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>JS Bin</title>
</head>
<body>
<p id="num1">5</p>
<p id="num2">5</p>
<p id="res">1</p>
</body>
<script>
var num1 = document.getElementById("num1").value;
var num2 = document.getElementById("num2").value;
var res = num1 + num2;
document.getElementById("res").innerHTML = res;
</script>
</html>
牧羊人nacy浏览 181回答 3
3回答
-
ITMISS
<!DOCTYPE html><html> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width"> <title>JS Bin</title> </head> <body> <p id="num1">5</p> <p id="num2">5</p> <p id="res">1</p> <script> window.onload = function () { var num1 = document.getElementById("num1").innerHTML; var num2 = document.getElementById("num2").innerHTML; var res = parseInt(num1) + parseInt(num2); document.getElementById("res").innerHTML = res; }; </script> </body></html> -
开心每一天1111
您应该使用 Number(document.getElementById("num1").innerText)，因为 p 标签的 value 属性不存在。 -
小怪兽爱吃肉
您已使用“值”而不是innerHTML 来获取数字。<!DOCTYPE html><html><head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width"> <title>JS Bin</title></head><body> <p id="num1">5</p> <p id="num2">5</p> <p id="res">1</p></body><script> var num1 = parseInt(document.getElementById("num1").innerHTML); var num2 = parseInt(document.getElementById("num2").innerHTML); var res = num1 + num2; document.getElementById("res").innerHTML = res;</script></html>
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相关分类
JavaScript