js-数组去重

function unique(arr) {
    debugger;
    var result = [], hash = {};
    for (var i = 0, elem; (elem = arr[i]) != null; i++) {
        if (!hash[elem]) {
            result.push(elem);
            hash[elem] = true;
        }
    }
    return result;
}

var aTest=[1,2,3,3,3,4,5,9];
console.log(unique(aTest))