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如何在HTML中将两个给定数字加在一起

[英]How do i add two giving numbers together in html

所以我的代码只是将它们加在一起,如果我输入的像是4 + 4,它给了我44,但我想像是4 + 4 = 8

 <html> <head> <title>Laskeminen</title> <body> <script language="JavaScript"> first = prompt("Enter your first number."); last = prompt("Enter your second number."); </script> <p id="first,last"></p> <script> var y = first var z = last var x = y + z; document.getElementById("first,last").innerHTML = x; </script> </head> </body> </html> 

您可以使用parseInt()

<html>
<head>
<title>Laskeminen</title>
<body>

<script language="JavaScript">
first = prompt("Enter your first number.");
last = prompt("Enter your second number.");
</script>

<p id="first,last"></p>

<script>
var y = parseInt(first)
var z = parseInt(last)
var x = y + z;
document.getElementById("first,last").innerHTML = x;
</script> 

</head>
</body>
</html>

使用Number()

 <html> <head> <title>Laskeminen</title> <body> <script language="JavaScript"> first = prompt("Enter your first number."); last = prompt("Enter your second number."); </script> <p id="first,last"></p> <script> var y = Number(first); var z = Number(last); var x = y + z; document.getElementById("first,last").innerHTML = x; </script> </head> </body> </html> 

prompt返回执行字符串连接的字符串。 使用parseInt执行加法。 您也有一些不必要的代码:

 var first = prompt("Enter your first number."); var last = prompt("Enter your second number."); var x = parseInt(first) + parseInt(last); document.getElementById("first,last").innerHTML = x; 
 <p id="first,last"></p> 

在第二个附加脚本中,您需要解析输入内容,因为当前它是一个字符串。 见下文

 first = prompt("Enter your first number."); console.log('User input is: ', typeof first) 

因此,因为当您添加文本时它们是字符串,所以它们被添加在一起,例如

 var text = 'ab'; var text1 = 'c'; if(text+text1 == 'abc'){ console.log('These have been added together and are equal') } 

因此,如果您要处理整数或整数,则需要立即解析,可以使用parseInt(**variabletoParse**)parseFloat(**variabletoParse**);

因此,您需要做的事情很明显:

 <html> <head> <title>Laskeminen</title> <body> <script language="JavaScript"> first = prompt("Enter your first number."); last = prompt("Enter your second number."); </script> <p id="first,last"></p> <script> var y = parseFloat(first); var z = parseFloat(last); var x = y + z; document.getElementById("first,last").innerHTML = x; </script> </head> </body> </html> 

您可以在值上使用parseFloat()将其转换为可以执行数学运算的数学浮点值:

 var first = prompt("Enter your first number."); var last = prompt("Enter your second number."); var y = parseFloat(first); var z = parseFloat(last); var x = y + z; document.getElementById("first,last").innerHTML = x; 
 <p id="first,last"></p> 

但是,如果只需要integers则可以执行parseInt()

 var first = prompt("Enter your first number."); var last = prompt("Enter your second number."); var y = parseInt(first); var z = parseInt(last); var x = y + z; document.getElementById("first,last").innerHTML = x; 
 <p id="first,last"></p> 

   <html>
<head>
<title>Laskeminen</title>
<body>
<p id="first,last"></p>
<script language="JavaScript">
first = prompt("Enter your first number.");
last = prompt("Enter your second number."); 
var y = parseInt(first);
var z = parseInt(last);
var x = y + z;
document.getElementById("first,last").innerHTML = x;
</script> 

</head>
</body>

</body>
</html>

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