Question

cars.length 啥意思???

<script>
cars=["BMW","Volvo","Saab","Ford"];
for (var i=0;i<cars.length;i++)
{
document.write(cars[i] + "<br>");
}
</script>

Answer 1

cars.length是数组的长度，用来确定数组的元素数，做为循环的终值，用以遍历整个数组。