<html>
<body>
<p>点击按钮以降序的索引方式循环数组。</p>
<button onclick="myFunction()">点我</button>
<p id="demo"></p>
<script>
function myFunction() {
var cars = ["BMW", "Volvo", "Saab", "Ford"];
var text = "";
var i;
for (i = cars.length - 1; i >= 0; i--) {
text += cars[i] + "<br>";
}
document.getElementById("demo").innerHTML = text;
}
</script>
</body>
</html>