array长度
books.length//3
新增
books.push()
删除
books.pop()
slice(开始,结束) 切割
books.slice()
反转 : 由新到旧
books.reverse()
concat array合并
var books = books1.concat(books2)
物件
var shop = {} shop[“name”] = “书店” shop[“phone”] = “02-27491527”
同上 shop.name = “书店” shop.phone = “02-27491527”
同上 shop = { name : “书店” phone : “02-27491527” }
append
ul
var books = ["1","2"]
$("ul").html("")
$("ul").append("<li>"+books[0]+"</li>")
$("ul").append("<li>"+books[1]+"</li>")