js 去除重复数组并排序实现代码

Array.prototype.unique1 = function () {
    var r = new Array();
    label:for(var i = 0, n = this.length; i < n; i++) {
        for(var x = 0, y = r.length; x < y; x++) {
            if(r[x] == this[i]) {
                continue label;
            }
        }
        r[r.length] = this[i];
    }
    return r;
}

Array.prototype.unique2 = function () {
    return this.sort().join(",,").replace(/(,|^)([^,]+)(,,2)+(,|$)/g,"$1$2$4").replace(/,,+/g,",").replace(/,$/,"").split(",");
}

Array.prototype.unique = function(){
    var a = {};
    var len = this.length;
    for(var i=0; i<len; i++)  {
        if(typeof a[this[i]] == "undefined") a[this[i]] = 1;
    }
    this.length = 0;
    for(var i in a) {
        this[this.length] = i;
    }
 
    return this;
}