JS Quicksort

function quicksort(input) {
    if(input.length === 0) return input;
            
    var head = input[0],
        tail = input.slice(1);
            
    var less = tail.filter(function(i) {
        return i < head ? true : false;
    });

    var greaterOrEqual = tail.filter(function(i) {
        return i >= head ? true : false;
    });

    return quicksort(less).concat([head], quicksort(greaterOrEqual));
            
}