//--------------------------------------------------------------------------
//一个数字或者数组是否属于另外一个数组数据（roading.net） 
function inArr(a1, a2) {
	if (typeof (a1) == "object") {
		var k = 0;
		for (var i in a2) {
			for (var j in a1) {
				if (a2[i] == a1[j]) {
					k++;
				}
			}
		}
		return k == a1.length ? true : false;
	} else {
		for (var j in a2) {
			if (a1 == a2[j]) {
				return true;
			}
		}
		return false;
	}
}
//
trace(inArr([1, 2, 8], [1, 2, 8]));
trace(inArr([1, 2], [1, 2, 8]));
trace(inArr(1, [1, 2, 8]));
trace(inArr(1, {a:1, b:2, c:8}));
//
trace(inArr(["d1", "d2", "d8"], ["d1", "d2", "d8"]));
trace(inArr(["d1", "d2"], ["d1", "d2", "d8"]));
trace(inArr("d1", ["d1", "d2", "d8"]));
trace(inArr("d1", {a:"d1", b:"d2", c:"d8"}));


//--------------------------------------------------------------------------
// 数组中最大最小元素索引
Array.prototype.min = function() {
	var i = this.length;
	var min = this[0];
	var idx = 0;
	while (i-->1) {
		if (this[i]<min) {
			min = this[idx=i];
		}
	}
	return idx;
};
Array.prototype.max = function() {
	var i = this.length;
	var max = this[0];
	var idx = 0;
	while (i-->1) {
		if (this[i]>max) {
			max = this[idx=i];
		}
	}
	return idx;
};

//usage

a = [1, 5, 2, 6, 8];
idx = a.min();
trace("Found minimum "+a[idx]+" at "+idx);
idx = a.max();
trace("Found maximum "+a[idx]+" at "+idx);


//--------------------------------------------------------------------------
// 比较两个数组是否相等
Array.prototype.equals = function(a){
	if (this == a) return true;
	var i = this.length;
	if (i != a.length) return false;
	while(i--) if (this[i] != a[i]) return false;
	return true;
}

//**** EXAMPLE ****

a = [1,2,3,4];
b = [1,2,3,4];
c = [1,2,3,5];
d = a;

trace(a.equals(b)); // true
trace(a.equals(c)); // false
trace(a.equals(d)); // true

//--------------------------------------------------------------------------
// 数组中两个元素交换位置
// ? MSA
// Version 1.3, 6.7.2002 - 6.11.2002
Array.prototype.exchange = function(i,j){
  if (i != j) with (this[i]) {
    this[i] = this[j];
    this[j] = valueOf();
  }
}

//--------------------------------------------------------------------------
// 乱序整个数组
// ? MSA
// Version 1.0, 4.10.2002
// Based on the Array.prototype.exchange

Array.prototype.shuffle = function() {
  var i = this.length-1;
  if (i) do {
    this.exchange(i, Math.floor(Math.random()*(i+1)));
  } while (--i);
}

//**** EXAMPLE ****

myArray = new Array (1,2,3,4,5,6,7,8,9,10);
myArray.shuffle();
trace (myArray);

//--------------------------------------------------------------------------
// 数组长度固定；向前，向后，当前位置三种方式逐个元素更新数据
Array.prototype._position = 0;
Array.prototype.current = function(newVal){
	if (!this.length) return undefined;
	if (!this._position) this._position = 0;
	else if (this._position >= this.length) this._position = this.length-1;
	if (newVal == undefined) return this[this._position];
	var orig = this[this._position];
	this[this._position] = newVal;
	return orig;
};
Array.prototype.next = function(newVal){
	if (!this.length) return undefined;
	if (this._position <= 0) this._position = 1;
	else if (this._position >= this.length-1) this._position = 0;
	else ++this._position;
	if (newVal == undefined) return this[this._position];
	var orig = this[this._position];
	this[this._position] = newVal;
	return orig;
};
Array.prototype.previous = function(newVal){
	if (!this.length) return undefined;
	if (this._position <= 0 || this._position >= this.length) this._position = this.length-1
	else --this._position;
	if (newVal == undefined) return this[this._position];
	var orig = this[this._position];
	this[this._position] = newVal;
	return orig;
};


//******** EXAMPLE ********

// cycle through an array with length 10 adding
// the time which the mouse was clicked using
// getTimer().  once the end is reached, the 
// _position is back to 0 and it repeats the
// cycle starting with the 'front' of the array
clickArray = new Array(10);
clickArray.current(getTimer());

this.onMouseDown = function(){
	clickArray.previous(getTimer());
	trace("["+clickArray+"]");
}

//--------------------------------------------------------------------------
// 判断一个值是否存在于数组当中，没有就在最后增加
// just verify an element is not already in before adding one.
array.prototype.addDistinct = function(val){
    for(var i in this) if(this[i] == val) return;
    return this.push(val);
}

//******** Example ********
var my_array = new Array("Tic", "Tac", "Toe");
my_array.addDistinct("Tac") // => doesn't push
trace(my_array);
my_array.addDistinct("Jim") // => all right
trace(my_array);

//--------------------------------------------------------------------------
// 整体偏移数组中元素位置
// Array.offset(): offsets and wraps the elements of an array n places.
// swell code by reggossra

Array.prototype.offset = function (offset) {
	if (offset < 0) {
		for (var i = 0; i < Math.abs(offset); i++) {
			// shift to get the first element, push it onto the end
			this.push(this.shift());
		}
	} else {
		for (var i = 0; i < Math.abs(offset); i++) {
			// pop to get the last element, unshift it onto the front
			this.unshift(this.pop());
		}
	}
};

//******** Example ********
letters = ["a","b","c","d","e"];
trace (letters); // output: a,b,c,d,e
letters.offset(-2);
trace (letters); // output: c,d,e,a,b

//--------------------------------------------------------------------------
// 数组中元素的平均数
Array.prototype.average = function() {
	var t = 0;
	for (var i in this) { if(typeof(this[i]) == "number") t+= this[i]; }
	return t/this.length;

};
//******** Example ********
bob = [2, 2, 8, 8];
trace(bob.average());

//--------------------------------------------------------------------------
// 删除数组中某个元素
Array.prototype.remove = function(piIndex) {
	laTmpArray = new Array();
	for (liIndex = 0; liIndex < this.length; liIndex ++) {
		if (liIndex != piIndex) laTmpArray[laTmpArray.length] = this[liIndex];
	}
	return(laTmpArray);
};