<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<script>
//数组去重:
function unique1(arr){
var n = [];
var len = arr.length;
for(var i=0;i<len;i++){
if(n.indexOf(arr[i])<0){
n.push(arr[i]);
}
}
return n;
}
function unique2(arr){
var obj = {},n = [];//利用了对象不会有重复属性的思想
var len = arr.length;
for(var i=0;i<len;i++){
if(!obj[arr[i]]){
obj[arr[i]] = true;
n.push(arr[i]);
}
}
return n;
}
function unique3(arr){
var n = [];
var len = arr.length;
for(var i=0;i<len;i++){
if(arr.indexOf(arr[i]) === i){
n.push(arr[i]);
}
}
return n;
}
var arr = [1,2,1,1,1,5,8,2];
console.log(unique3(arr));
console.log(unique2(arr));
console.log(unique1(arr));
//结果均为[1,2,5,8]
</script>
</body>
</html>