<!DOCTYPE html>charset="utf-8"W3Cschool教程(w3cschool.cn)id="demo"单击按钮创建一个数组,调用ucase()方法, 并显示结果。onclick="myFunction()"点我Array.prototype.myUcase=function(){for (i=0;i<this.length;i++){this[i]=this[i].toUpperCase();}}function myFunction(){var fruits = ["Banana", "Orange", "Apple", "Mango"];fruits.myUcase();var x=document.getElementById("demo");x.innerHTML=fruits;}