如何在JavaScript中求和2个值

Question

Everything else displays correctly, I just can not get a new total to populate, once another code is entered in. They just display side by side. 其他所有内容均可正确显示，一旦输入其他代码，我将无法填充新的总数。它们只能并排显示。 I only need to figure out how to get it to take the code that is listed from my dropdown, then combine it with whatever new options I may select. 我只需要弄清楚如何获取下拉菜单中列出的代码，然后将其与我可能选择的任何新选项结合起来。

    <script>
        function ChangeImage() {
            document.getElementById("imgSweater").src = document.getElementById("selImage").value;
        }

        function myCart() {
            var sweater = document.getElementById("selImage").value;
            var quantity = document.getElementById("txtQty").value;
            var tall = document.getElementById("chkTall").checked;
            var Total;
            var type;
            var price;

            switch (sweater) {
                case "Cardigan":
                    price = parseInt(69.00 * quantity);
                    break;
                case "Crew":                  
                    price = parseInt(29.50 * quantity);
                    break;
                case "Zip-Front":
                    price = parseInt(39.50 * quantity);
                    break;
                case "V-Neck":
                    price = parseInt(59.00 * quantity);
                    break;
                default:
                    alert("Error");

            }
            if (tall) {
                price += 5;
            }
            if (Total) {
                divTotal > 0 + divCart;
            }
            document.getElementById("divCart").innerHTML += quantity + " </nbsp>  " + sweater + " " + "@" + " " + price + "<br />";
            document.getElementById("divTotal").innerHTML += quantity * parseFloat(price);
            if (divTotal > 0 ) {
                document.getElementById("divTotal").innerHTML + document.getElementById("divCart") + price + Total;
            }
        }

        function myClear() {
            document.getElementById("divTotal").innerHTML = "";
            document.getElementById("divCart").innerHTML =  "";
            document.getElementById("txtQty").value = "";
        }

    </script>
</head>
<body>
    <h1>LL Bean Sweaters</h1>

    <table class="auto-style1">
        <tr>
            <td style="border-style: solid; border-width: thin">
                <select id="selImage" onchange="return ChangeImage()">
                    <option value="Cardigan">Cardigan</option>
                    <option value="Crew">Crew</option>
                    <option value="Zip-Front">Zip-Front</option>
                    <option value="V-Neck">V-Neck</option>
                </select></td>
            <td style="border-style: solid; border-width: thin" rowspan="4">
                <img id="imgSweater" alt="" src="Cardigan.jpg" height="300px" /></td></tr>

        <tr>
            <td style="border-style: solid; border-width: thin">Quantity:
                <input id="txtQty" type="text" /></td>
        </tr>
        <tr>
            <td style="border-style: solid; border-width: thin">
                <input id="chkTall" type="checkbox" /> <label for="chkTall">Tall</label></td>
        </tr>
        <tr>
            <td style="border-style: solid; border-width: thin">
                <input id="btnCart" type="button" value="Add to Cart" onclick="return myCart()" /></td>
        </tr>
        <tr>
            <td style="border-style: solid; border-width: thin" colspan="2">
                <div id="divCart">$</div>
            </td>
        </tr>
        <tr>
            <td style="border-style: solid; border-width: thin">Total:</td>
            <td style="border-style: solid; border-width: thin">
                <div id="divTotal">$ </div>
            </td>
        </tr>
        <tr>
            <td style="border-style: solid; border-width: thin">&nbsp;</td>
            <td style="border-style: solid; border-width: thin">
                <input id="btnClear" type="button" value="Clear" onclick="return myClear()" /></td>
        </tr>
    </table>

</body>
</html>

Answer 1

Is this 这是

        if (divTotal > 0 ) {
            document.getElementById("divTotal").innerHTML + document.getElementById("divCart") + price + Total;
        }

Supposed to be this? 应该是这个吗？

        if (divTotal > 0 ) {
            document.getElementById("divTotal").innerHTML += document.getElementById("divCart").innerHTML + price + Total;
        }

Answer 2

   if (divTotal > 0 ) {
        document.getElementById("divTotal").innerHTML + document.getElementById("divCart") + price + Total;
    }

Your are adding two values correctly but you need to assign also to something. 您正确地添加了两个值，但是您还需要将其分配给某些值。
Like 喜欢

 if (divTotal > 0 ) {
        var total=document.getElementById("divTotal").innerHTML + document.getElementById("divCart") + price + Total;
    }

try replacing DivTotal by 尝试将DivTotal替换为

var insideDiv=document.getElementById(divTotal ).innerHTML;
var divt=parseInt(insideDiv);

如何在JavaScript中求和2个值

问题描述

2 个解决方案

解决方案1
0 2015-10-24 19:28:19

解决方案2
0 2015-10-24 19:35:54

如何在JavaScript中求和2个值

问题描述

2 个解决方案

解决方案1 0 2015-10-24 19:28:19

解决方案2 0 2015-10-24 19:35:54

解决方案1
0 2015-10-24 19:28:19

解决方案2
0 2015-10-24 19:35:54