我有这个HTML代码：
<form id="form1" name="form1" method="post" action="">
a <input type="text" name="item[]" value="1" /> <br />
b <input type="text" name="item[]" value="1" /> <br />
c <input type="text" name="item[]" value="1" />
</form>
我似乎无法用语法从文本字段数组中拉出长度，是否有一些明显的JavaScript方式（没有Jquery请）这样做？我试过了
<script language="javascript">
//Tried these combination
alert(document.form1.item.length);
alert(document.form1.item[].length);
alert(document.form1.elements['item'].length);
alert(document.form1.elements['item[]'].length);
</script>
答案 0 :(得分：2)
var inputCount = document.getElementById('form1').getElementsByTagName('input').length;
请注意，严格来说，您的输入元素不构成数组。它们是DOM中的节点，因此您必须将它们作为数组找到。
我知道你说“没有jQuery”，但在这个时代，当人们拒绝使用这样的工具时，它真的让我感到困惑。他们解决了很多的问题，否则你最终会自己解决这些问题。
答案 1 :(得分：0)
<script language="JavaScript" type="text/javascript">
<!--
function Total() {
var i, ordertotal, discount, total;
ordertotal = 0;
nitems = 4
for (i=1; i<nitems+1; i++) {
eval("document.orderform.Item" + i + "Total.value = '';");
if (document.forms[0]['Item'+i].checked==true){
eval("total=Number(document.orderform['ItemPrice[' + i + ']' + '[' + 0 + ']'].value);");
eval("document.orderform.Item" + i + "Total.value=Currency(total)");
eval("ordertotal = ordertotal + total;");
}
}
document.orderform.OrderTotal.value = Currency(ordertotal);
discount = ordertotal * .5
document.orderform.Discount.value = Currency(discount);
document.orderform.GrandTotal.value = Currency(ordertotal + discount);
}
function Currency(anynum) {
anynum = "" + eval(anynum);
intnum = parseInt(anynum);
intnum = Math.abs(intnum);
intstr = ""+intnum;
if (intnum >= 1000) {
intlen = intstr.length
temp1=parseInt(""+(intnum/1000))
temp2=intstr.substring(intlen-3,intlen)
intstr = temp1+","+temp2
}
if (intnum >= 1000000) {
intlen = intstr.length
temp1=parseInt(""+(intnum/1000000))
temp2=intstr.substring(intlen-7,intlen)
intstr = temp1+","+temp2
}
decnum = Math.abs(parseFloat(anynum)-parseInt(anynum));
decnum = decnum * 100;
decstr = "" + Math.abs(Math.round(decnum))
if (decstr.length>2) {decstr=decstr.substring(0,2)}
while (decstr.length < 2) {decstr="0"+decstr}
retval = intstr + "." + decstr
if (anynum < 0) {
retval="("+retval+")"
}
return "$"+retval
}
//-->
</script>
<form name="orderform">
<table border="0" cellpadding="0" cellspacing="0" width="723">
<tr>
<th>Java script to calculate price with the double dimension arrays </th>
<th>origional script modified by amarjit lehal :lehal2@hotmail.com</th>
<th width="89" align="center" bgcolor="#F0F8FF" height="33">Item</th>
<th width="356" bgcolor="#F0F8FF" height="33">Description</th>
<th width="100" align="center" bgcolor="#F0F8FF" height="33">Price</th>
<th width="95" align="center" bgcolor="#F0F8FF" height="33">Total</th>
</tr>
<tr>
<td width="89" align="center" height="23" bgcolor="#F0F8FF">
<input type="checkbox" name="Item1" value="1" onClick="Total();"></td>
<td width="356" height="23" bgcolor="#F0F8FF">Item1!</td>
<td width="100" align="center" height="23" bgcolor="#F0F8FF">$
<input type="text" onfocus="this.blur();" name="ItemPrice[1][0]" size="9" value="5.50"></td>
<td width="95" align="center" height="23" bgcolor="#F0F8FF">
<input type="text" onfocus="this.blur();" name="Item1Total" size="10"></td>
</tr>
<tr>
<td width="89" align="center" height="23" bgcolor="#F0F8FF">
<input type="checkbox" name="Item2" onClick="Total();" value="1"></td>
<td width="356" height="23" bgcolor="#F0F8FF">Item2</td>
<td width="100" align="center" height="23" bgcolor="#F0F8FF">$
<input type="text" onfocus="this.blur();" name="ItemPrice[2][0]" size="9" value="10.50"></td>
<td width="95" align="center" height="23" bgcolor="#F0F8FF">
<input type="text" onfocus="this.blur();" name="Item2Total" size="10"></td>
</tr>
<tr>
<td width="89" align="center" height="23" bgcolor="#F0F8FF">
<input type="checkbox" name="Item3" onClick="Total();" value="1"></td>
<td width="356" height="23" bgcolor="#F0F8FF">Item3</td>
<td width="100" align="center" height="23" bgcolor="#F0F8FF">$
<input type="text" onfocus="this.blur();" name="ItemPrice[3][0]" size="9" value="20.50"></td>
<td width="95" align="center" height="23" bgcolor="#F0F8FF">
<input type="text" onfocus="this.blur();" name="Item3Total" size="10"></td>
</tr>
<tr>
<td width="89" align="center" height="23" bgcolor="#F0F8FF">
<input type="checkbox" name="Item4" onClick="Total();" value="1"></td>
<td width="356" height="23" bgcolor="#F0F8FF">Item4</td>
<td width="100" align="center" height="23" bgcolor="#F0F8FF">$
<input type="text" onfocus="this.blur();" name="ItemPrice[4][0]" size="9" value="30.50"></td>
<td width="95" align="center" height="23" bgcolor="#F0F8FF">
<input type="text" onfocus="this.blur();" name="Item4Total" size="10"></td>
</tr>
<tr>
<td width="546" align="center" height="23" colspan="3" bgcolor="#F0F8FF">
<div align="right">
<p>Order Total
</div>
</td>
<td width="95" align="center" height="23" bgcolor="#F0F8FF">
<input type="text" onfocus="this.blur();" name="OrderTotal" size="10"></td>
</tr>
<tr>
<td width="546" align="center" height="23" colspan="3" bgcolor="#F0F8FF">
<div align="right">
<p>Discount
</div>
</td>
<td width="95" align="center" height="23" bgcolor="#F0F8FF">
<input type="text" onfocus="this.blur();" name="Discount" size="10"></td>
</tr>
<tr>
<td width="546" align="center" height="23" colspan="3" bgcolor="#F0F8FF">
<div align="right">
<p>Grand Total
</div>
</td>
<td width="95" align="center" height="23" bgcolor="#F0F8FF">
<input type="text" onfocus="this.blur();" name="GrandTotal" size="10"></td>
</tr>
</table>
<p><input name="Submit" type="Submit" value="Submit"></p>
</form>