利用es6语法
var arr = [1,2,1,2,1,2,3,3]
console.log(Array.from(new Set(arr))) //[1,2,3]
js
var arr2 = [];
var arr = [1,2,1,2,1,2,3,3];
for (var i=0;i<arr.length;i++) {
if(arr2.indexOf(arr[i] == -1)){
arr2.push(arr[i])
}
}
console.log(arr2) //[1,2,3]
原文：https://www.cnblogs.com/cai001018/p/14592685.html