简单去重

var arr = [1,2,5,3,4,4,4,4,4,4];
var obj = {}
for(var i  in arr){
   obj[arr[i]] = 100;
}
console.log( obj);

　　es6：

	var arr = [1,2,3,4,4,2,4,45,6,6,7,7,"dff","dff",'7',{'dd':'dd'}];
	console.log(...new Set(arr));