JavaScript 배열에서 중복 값을 제거하려면 어떻게 해야 합니까?

uniq = [...new Set(array)];

uniqueArray = a.filter(function(item, pos) {
    return a.indexOf(item) == pos;
});

function uniq(a) {
    var seen = {};
    return a.filter(function(item) {
        return seen.hasOwnProperty(item) ? false : (seen[item] = true);
    });
}

function uniq(a) {
    var prims = {"boolean":{}, "number":{}, "string":{}}, objs = [];

    return a.filter(function(item) {
        var type = typeof item;
        if(type in prims)
            return prims[type].hasOwnProperty(item) ? false : (prims[type][item] = true);
        else
            return objs.indexOf(item) >= 0 ? false : objs.push(item);
    });
}

function uniq(a) {
    return a.sort().filter(function(item, pos, ary) {
        return !pos || item != ary[pos - 1];
    });
}

function uniqBy(a, key) {
    var seen = {};
    return a.filter(function(item) {
        var k = key(item);
        return seen.hasOwnProperty(k) ? false : (seen[k] = true);
    })
}