![JS数组[2, 5, 2, 5, 10, 12],如何循环打印 （2, 5, 10, 12） 不要打印重复的值，这个循环怎么写。](/aiimages/JS%E6%95%B0%E7%BB%84%5B2%2C+5%2C+2%2C+5%2C+10%2C+12%5D%2C%E5%A6%82%E4%BD%95%E5%BE%AA%E7%8E%AF%E6%89%93%E5%8D%B0+%EF%BC%882%2C+5%2C+10%2C+12%EF%BC%89+%E4%B8%8D%E8%A6%81%E6%89%93%E5%8D%B0%E9%87%8D%E5%A4%8D%E7%9A%84%E5%80%BC%EF%BC%8C%E8%BF%99%E4%B8%AA%E5%BE%AA%E7%8E%AF%E6%80%8E%E4%B9%88%E5%86%99%E3%80%82.png)
//js对象如何实现数组索引功能并且自定义自己的方法 4种方法
function Ele(e){
var a = {show:function(){alert("name")}}
var all = document.getElementsByTagName(e)
for(var i =0 i<all.lengthi++)
{
a[i] = all[i]
}
a.length = all.length
return a
}
function Ele2(e){
var a = new Object()
a.show = function(){
alert("name")
}
var all = document.getElementsByTagName(e)
for(var i =0 i<all.lengthi++)
{
a[i] = all[i]
}
a.length = all.length
return a
}
function Ele3(e)
{
this.show = function(){
alert("name")
}
var all =document.getElementsByTagName("p")
for(var i =0 i<all.lengthi++)
{
this[i] = all[i]
}
this.length = all.length
}
<pre name="code" class="html"> function Ele4(e)
{
var array = function(){}
array.prototype = new Array()
array.prototype.show = function(){
alert("name")
}
var all = document.getElementsByTagName(e)
for(var i =0 i<all.lengthi++){
array.prototype.push(all[i])
}
return new array()
}
data[0].username 首先data是数组,数组使用的下标0 -- length-1 取数组元素,然互data[0] 才是一个json对象,包含有username,password两个属性
