javascript----数组的方法

1---join()
//1----->join()方法将数组中所有元素都转化《《字符串》》
    //并连接在一起
    //array.join()方法是string.split()方法逆向操作

    var a=[1,2,3];//创建一个包含三个元素的素组
    var c=["多多","梦曦","洛瑶"];
    console.log(a.join())
    console.log(a.join(" "))
    console.log(a.join(""))

//2---->reverse()  将数组中元素颠倒顺序，返回逆序的数组
    //下面的代码使用reverse 和join()方法生成字符串
    var myarray=["狗狗","毛毛","多多","阿黄"]
    console.log(myarray.reverse());
    //顺讯反转 ，以字符串输出结果
    console.log(myarray.reverse().join())

 //3---->array.sort()方法将数组中元素排序
    //并返回排序后的数组，
    //数组元素以字母表

    var myArray=["dudu","xiaoxiao","diandian","bibi"];

    console.log(myArray.sort())
    console.log(myArray.sort().join())
    var MyArray=[3,2,1,5,6];
    console.log(MyArray.sort())
    var MyArray1=[111,44,66,77];
    MyArray1.sort();
    MyArray1.sort(function(a,b){
        return a-b;

    });
    MyArray1.sort(function(a,b){
        return b-a;
    });

  //4----->concat() 连接数组，对数组合并
    var MyArray2=[32,23,14,15,6];
    var MyArray3=["花花","梦瑶","叶子","欣欣"]
    mm= MyArray2.concat(MyArray3,myArray)
    console.log(mm)
    c= MyArray2.concat(4,5,66)
    console.log(c)
    m=MyArray3.concat(["gouzi","小粒","多多"])
    console.log(m)

//5----->Arry.slice()方法返回指定数组的一个片段或子数组
    //两个参数分别指定了开始的结束位置
    MyArray4=["伤心地","梦瑶池","滴滴哒哒","小狐狸"]
    d=MyArray4.slice(1,2).concat(MyArray3)
    console.log(d)

    //6----splice()方法是指在数组中插入或删除元素通用方法
    //splice和slice拥有非常相似的名字
    MyArray5=["香蕉","苹果","梨","花生","地瓜"]
    console.log(MyArray5.splice(3))
    console.log(MyArray5.splice(1,3))

    //7---push()和pop()
    //---push()在末尾添加元素，并返回新的<<长度>>
    //---pop()删除末尾的最后一个元素
    console.log("push方法是添加字符，返回一个新的长度")
    MyArray6=["狗儿","猫猫","小猪","小白"];
    console.log(MyArray6.push("小青蛇"))
    MyArray7=["狗儿","猫猫","小猪","小白"];
    console.log("pop（）删除末尾，返回的是删除的元素")
    console.log(MyArray7.pop())

 //8---->unshift() 和shift()
    /***
     * unshift()在头部添加一个或多个元素，最后返回新的长度
     * shift()删除数组第一个元素并将其返回
     *
     */
    MyArray8=["农夫三泉","怡宝","康师傅","和其正","金银花"]
    console.log(MyArray8.unshift("雪碧","小花咪"))
    MyArray8=["农夫三泉","怡宝","康师傅","和其正","金银花"]
    console.log(MyArray8.shift())

    //---->forEach()方法从头至尾遍历数组