根据属性找标签

<script type="text/javascript">

    function checkAll(allNode){
        //找到所有的的选项
        var items = document.getElementsByName("item");
        //找到全选按钮的对象
        //var allNode = document.getElementsByName("all")[0];
        for(var i = 0 ; i<items.length ; i++){
            items[i].checked =     allNode.checked;
        }
    }
    
    
    function getSum(){
        var items = document.getElementsByName("item");
        var sum = 0;
        for(var i = 0 ; i<items.length ; i++){
            if(items[i].checked){
                sum += parseInt(items[i].value);
            }    
        }    
        var spanNode = document.getElementById("sumid");
        spanNode.innerHTML = ("&nbsp;&nbsp;&nbsp;&yen;"+sum).fontcolor("green");
    }
    


</script>
<body>
    <div>商品列表</div>
        <input type="checkbox" name="item" value="3000" />笔记本电脑3000元<br />
        <input type="checkbox" name="item" value="1800"  />笔记本电脑1800元<br />
        <input type="checkbox" name="item" value="300"  />笔记本电脑300元<br />
        <input type="checkbox" name="item" value="3000"  />笔记本电脑3000元<br />
        <input type="checkbox" name="item" value="3000"  />笔记本电脑3000元<br />
        <input type="checkbox" name="item" value="3000"  />笔记本电脑3000元<br />
        <input type="checkbox" name="all" onclick="checkAll(this)"  /> 全选<br />
        <input type="button" value="总金额:" onclick="getSum()" /><span id="sumid"></span>
</body>
原文地址:https://www.cnblogs.com/linst/p/5723543.html