function getLength()
{
var length = 0;
for(i=0;i<document.all.tags("input").length;i++)
{
if(document.all.tags("input")[i].name=="product")
length++;
}
return length;
}
{
var length = 0;
for(i=0;i<document.all.tags("input").length;i++)
{
if(document.all.tags("input")[i].name=="product")
length++;
}
return length;
}
有一个时 没有length这个属性
只有大于一个时才成立
alert(text.test.length);
}</script>
<form name= "text">
<input type= "text" name= "test" value= "">
<input type= "text" name= "test" value= "">
<input type= "text" name= "test" value= "">
<input type= "text" name= "test" value= "">
<input type= "text" name= "test" value= "">
<input type= "text" name= "test" value= "">
<input type= "text" name= "test" value= "">
<input type= "text" name= "test" value= "">
<input type= "text" name= "test" value= "">
<input type= "button" onclick= "javascript:noit()" >
</form>
<script>function noit(form){
var len = 0;
for(i=0;i<form.elements.length;i++){
if(form.elements[i].name=="test"){
len ++;
}
}
alert(len);
}</script>
<form name= "text">
<input type= "text" name= "test" value= "">
<input type= "button" onclick= "javascript:noit(this.form)" >
</form>
<script language="JavaScript" type="text/JavaScript">
if(document.all.text.length){alert(document.all.text.length)}
else{if(document.all.text){alert(1)}}
</script>
//如果只判断文本框则再附加相应条件