<!DOCTYPE html>charset="utf-8"W3Cschool教程(w3cschool.cn)id="demo"单击按钮显示“苹果”最后一次出现的位置:onclick="myFunction()"点我function myFunction(){var fruits=["Banana","Orange","Apple","Mango","Banana","Orange","Apple","Mango"];var a=fruits.lastIndexOf("Apple")var x=document.getElementById("demo");x.innerHTML=a;}注意:lastIndexOf方法在JavaScript 1.6被引进,在Internet Explorer 8或更早的版本中不支持。