javascript - Nan 来自 javascript 的结果

Question

嗨，这是我的第一篇文章，也是我第一次尝试 javascript(我喜欢 php)。问题是我从我的 js 中得到了 NaN 结果(如果我能得到要移植的代码!)

<script type="text/javascript">
    function Running_Total() { 
        alert('firing');
        var cost1 = "'.$_SESSION['75gmcost'].'"+""; 
        var cost2 = "'.$_SESSION['100gmcost'].'"+""; 
        var cost3 = "'.$_SESSION['1kgcost'].'";+""; 
        var cost4 = "'.$_SESSION['c75gmcost'].'"+""; 
        var qty1 = "'.$_SESSION['qty75gm'].'"+""; 
        var qty2 = "'.$_SESSION['qty100gm'].'"+""; 
        var qty3 = "'.$_SESSION['qty1kg'].'"+""; 
        var qty4 = "'.$_SESSION['qtyc75gm'].'"+""; 
        var sum = 0;
        sum += cost1 * qty1;
        sum += cost2 * qty2;
        sum += cost3 * qty3;
        sum += cost4 * qty4;
        $('#tot_cost').empty();
        $('#tot_cost').append(sum);
    }
</script>

我正在尝试从表单输入中求和订单总数，但对 js 的了解不够，无法解决 Nan 问题。我想我的 php 变量必须更改以适应 js，但不知道该怎么做？ ##

Answer 1

尝试用以下内容替换代码中的 var 分配:

var cost1 = {$_SESSION['75gmcost']};
var cost2 = {$_SESSION['100gmcost']};
var cost3 = {$_SESSION['1kgcost']}; 
var cost4 = {$_SESSION['c75gmcost']}; 
var qty1 = {$_SESSION['qty75gm']};
var qty2 = {$_SESSION['qty100gm']}; 
var qty3 = {$_SESSION['qty1kg']};
var qty4 = {$_SESSION['qtyc75gm']}; 

连接字符串会产生一个在 JavaScript 中不被解释为数字 (NaN) 的值。

这是一个警告“4”的工作示例

<?php
    session_start();
    $_SESSION['75gmcost'] = 1; 
    $_SESSION['100gmcost'] = 1;  
    $_SESSION['1kgcost'] = 1; 
    $_SESSION['c75gmcost'] = 1; 
    $_SESSION['qty75gm'] = 1;  
    $_SESSION['qty100gm'] = 1; 
    $_SESSION['qty1kg'] = 1; 
    $_SESSION['qtyc75gm'] = 1; 

    print <<< HERE
           <script type="text/javascript">
    function Running_Total() { 
            alert('firing');
        var cost1 = {$_SESSION['75gmcost']}; 
        var cost2 = {$_SESSION['100gmcost']};
        var cost3 = {$_SESSION['1kgcost']};
        var cost4 = {$_SESSION['c75gmcost']}; 
        var qty1 = {$_SESSION['qty75gm']};
        var qty2 = {$_SESSION['qty100gm']}; 
        var qty3 = {$_SESSION['qty1kg']};
        var qty4 = {$_SESSION['qtyc75gm']}; 
        var sum = 0;
        sum += cost1 * qty1;
        sum += cost2 * qty2;
        sum += cost3 * qty3;
        sum += cost4 * qty4;
        alert(sum);
    }
    Running_Total();
    </script>
    HERE;
?>