webjs--hash数组去重

 <script type="text/javascript">function unique(arr){var hash=[];hash[arr[0]]=1;for (var i=1;i<arr.length ;i++ ){if(hash[arr[i]]===undefined){hash[arr[i]]=1}}var keys=[],i=0;for (keys[i++] in hash);console.log(keys);}console.time('unique');unique([20,50,20,40,50,10,20]);console.timeEnd('unique');</script>