Array Helpers for JavaScript + jQuery

JS_Array_Helpers.js

// For getting unique values in array
// usage:
//      var duplicates = [1,3,4,2,1,2,3,8];
//      var uniques = duplicates.unique(); // result = [1,3,4,2,8]
Array.prototype.contains = function(v) {
    for(var i = 0; i < this.length; i++) {
        if(this[i] === v) return true;
    }
    return false;
};
Array.prototype.unique = function() {
    var arr = [];
    for(var i = 0; i < this.length; i++) {
        if(!arr.contains(this[i])) {
            arr.push(this[i]);
        }
    }
    return arr; 
}

// SORT ARRAY BY NUMBER, NOT ALPHABETICAL
// Usage: myArr = myArr.sortNumber();
Array.prototype.sortNumber = function(){
    return this.sort(function(a,b){return b - a});
}

// REMOVE ITEM FROM ARRAY BY VALUE
// This can be a global function or a method of a custom object, if you aren't allowed to 
// add to native prototypes. It removes all of the items from the array that match any of the arguments.
Array.prototype.remove = function() {
    var what, a = arguments, L = a.length, ax;
    while (L && this.length) {
        what = a[--L];
        while ((ax = this.indexOf(what)) !== -1) {
            this.splice(ax, 1);
        }
    }
    return this;
};