Question

当我用HTML提交表单时，我正试图在Javascript中进行一些控制。

除了需要检查2个字段之和的情况外，Evertyhing工作得很好。

<script type="text/javascript">
function validation()
{
var count=0;
if((document.getElementsByName("people")[0].selectedIndex) == "")
    {alert("How many PEOPLE?"); count++;}
else if((document.getElementsByName("amount")[0].selectedIndex) == "")
    {alert("AMOUNT has to be at least 1."); count++;}
else if((document.getElementsByName("deposit")[0].value) == "")
    {alert("DEPOSIT cannot be empty."); count++;}
else if((document.getElementsByName("deposit")[0].value) < "20")
    {alert("DEPOSIT must be at least 20."); count++;}
else if((document.getElementsByName("topay")[0].value) == "")
    {alert("Mark 0 in TO PAY if they dont have to pay more."); count++;}
else if( (  (document.getElementsByName("deposit")[0].value) + (document.getElementsByName("topay")[0].value) ) < "40")
    {alert("The minimum price of this product is 40"); count++;}

else if((document.getElementsByName("seller")[0].value) == "")
    {alert("Who is the SELLER?"); count++;}
else if(isNaN(document.getElementsByName("topay")[0].value))
    {alert("TO PAY must be a number"); count++;}
else if(isNaN(document.getElementsByName("people")[0].value))
    {alert("PEOPLE must be a number"); count++;}
else if(isNaN(document.getElementsByName("deposit")[0].value))
    {alert("DEPOSIT must be a number"); count++;}
else if(isNaN(document.getElementsByName("amount")[0].value))
    {alert("AMOUNT must be a number"); count++;}
return (count==0);
}
</script>

我无法解决的问题是：

else if( (((document.getElementsByName("deposit")[0].value) + (document.getElementsByName("topay")[0].value)) < "40)")
    {alert("The minimum price of this product is 40"); count++;}

我希望它检查（存款+ topay）＆lt; 40.我注意到这个代码只是检查（存款＆lt; 40）并且我不明白为什么。

你能帮帮我吗？

Answer 1

'+'运算符在条件语句中充当连接运算符（或通常执行连接）。

因此，为了使其执行加法操作，

else if( ((parseInt(document.getElementsByName("deposit")[0].value) + parseInt(document.getElementsByName("topay")[0].value)) < 40))
    {alert("The minimum price of this product is 40"); count++;}

Answer 2

var abc = parseInt（（document.getElementsByName（＆＃34;存＆＃34;）[0]。价值）+（document.getElementsByName（＆＃34; topay＆＃34;）[0]。价值））if（abc＆lt;＆＃34; 40＆＃34;）{alert（＆＃34; h＆＃34; + abc）; }

Answer 3

将您的if条件更改为此

if( (((document.getElementsByName("deposit")[0].value) + (document.getElementsByName("topay")[0].value)) < 40))

在javascript中控制输入框的总和

3 个答案: