var arr = new Array();
arr[0] = "aaa";
arr[1] = "bbb";
arr[2] = "ccc";
//alert(arr.length);//3
arr.pop();
//alert(arr.length);//2
//alert(arr[arr.length-1]);//bbb
arr.pop();
//alert(arr[arr.length-1]);//aaa
//alert(arr.length);//1
var arr2 = new Array();
//alert(arr2.length);//0
arr2[0] = "aaa";
arr2[1] = "bbb";
//alert(arr2.length);//2
arr2.pop();
//alert(arr2.length);//1
arr2 = arr2.slice(0,arr2.length-1);
//alert(arr2.length);//0
arr2[0] = "aaa";
arr2[1] = "bbb";
arr2[2] = "ccc";
arr2 = arr2.slice(0,1);
alert(arr2.length);//1
alert(arr2[0]);//aaa
alert(arr2[1]);//undefined

var a = [1,2,3,4,5];
var b = a.shift(); //a：[2,3,4,5]   b：1

var a = [1,2,3,4,5];
var b = a.unshift(-2,-1); //a：[-2,-1,1,2,3,4,5]   b：7

var a = [1,2,3,4,5];
var b = a.pop(); //a：[1,2,3,4]   b：5//不用返回的话直接调用就可以了

var a = [1,2,3,4,5];
var b = a.push(6,7); //a：[1,2,3,4,5,6,7]   b：7

var a = [1,2,3,4,5];
var b = a.concat(6,7); //a：[1,2,3,4,5]   b：[1,2,3,4,5,6,7]

var a = [1,2,3,4,5];
var b = a.splice(2,2,7,8,9); //a：[1,2,7,8,9,5]   b：[3,4]
var b = a.splice(0,1); //同shift
a.splice(0,0,-2,-1); var b = a.length;//同unshift
var b = a.splice(a.length-1,1);//同pop
a.splice(a.length,0,6,7); var b = a.length; //同push

var a = [1,2,3,4,5];
var b = a.reverse(); //a：[5,4,3,2,1]   b：[5,4,3,2,1]

var a = [1,2,3,4,5];
var b = a.sort(); //a：[1,2,3,4,5]   b：[1,2,3,4,5]

var a = [1,2,3,4,5];
var b = a.slice(2,5); //a：[1,2,3,4,5]   b：[3,4,5]

var a = [1,2,3,4,5];
var b = a.join("|"); //a：[1,2,3,4,5]   b："1|2|3|4|5"

/**
* 字符串处理函数
*/
function StringBuffer() {
var arr = new Array;
this.append = function(str) {
    arr[arr.length] = str;
};
this.toString = function() {
    return arr.join("");//把append进来的数组ping成一个字符串
};
}

/**
*把数组转换成特定符号分割的字符串
*/
function arrayToString(arr,separator) {
if(!separator) separator = "";//separator为null则默认为空
    return arr.join(separator);
}
/**
* 查找数组包含的字符串
*/
function arrayFindString(arr,string) {
var str = arr.join("");
    return str.indexOf(string);
}