HTML PART
<select id="carlist" name="cars">
<option value="volvo">Volvo</option>
<option value="fiat">Fiat</option>
<option value="audi">Audi</option>
</select>
JAVASCRIPT PART
cars=["volvo","fiat","audi"];
var best = "fiat";
for (var i=0;i<cars.length;i++)
{
if (cars.value == best.value)
(
document.getElementById('carlist').selectedIndex= 2;
}
下拉的最终结果始终是audi,因为最后一行中的.selectIndex为2。我在最后一行做了哪些更改,以便下拉值根据变量“best”而变化?
答案 0 :(得分:4)
cars=["volvo","fiat","audi"];
var best = "audi";
for (var i=0;i<cars.length;i++)
{
if (cars[i] == best)
{
document.getElementById('carlist').selectedIndex= i;
}
}
答案 1 :(得分:1)
试试这个
var selectobject=document.getElementById("carlist")
for (var i=0; i<selectobject.length; i++){
if(selectobject.options[i].value == best)
ocument.getElementById('carlist').selectedIndex= i;
}
}
将此逻辑写入for循环
或
cars=["volvo","fiat","audi"];
var best = "fiat";
for (var i=0;i<cars.length;i++)
if (cars[i] == best)
document.getElementById('carlist').selectedIndex= i;