<script>

    function SongManager(){

        this.songList = null;

    }

    //在当前对象的方法中，调用当前对象的其他方法，需要使用this

    //例如 在 removeSong方法中调用 selectSong  this.selectSong

    SongManager.prototype = {

        init:function (songList) {

            this.songList = songList;

        },

        addSong: function (song){

            this.songList.push(song);

        },

        removeSong:function (songName){

            var song = this.selectSong(songName);

            if(song == null){

                throw "您要删除的歌曲不存在！请重新尝试";

            }

            var index = this.songList.indexOf(song);

            this.songList.splice(index, 1);

        },

        updateSong: function (songName, singer) {

            var song = this.selectSong(songName);

            if(song == null){

                throw "您要修改的歌曲不存在！请重新尝试";

            }

            song.singer = singer;

        },

        selectSong: function (songName) {

            for (var k = 0; k < this.songList.length; k++) {

                var song = this.songList[k];

                if(song.songName == songName){

                    return song;

                }

            }

            return null;

        }

    };

    var pwbDEManager = new SongManager();

    pwbDEManager.init([

        {

            songName:"青藏高原",

            singer:"潘文斌"

        },

        {

            songName:"我的换板鞋，摩擦摩擦最时尚",

            singer:"约翰逊，庞麦郎"

        }

    ]);

    pwbDEManager.addSong({

        songName:"东风破",

        singer:"Jay Chou"

    })

    var gjbDEManager = new SongManager();

    gjbDEManager.init([

        {

            songName:"两只老虎",

            singer:"高金彪"

        },

        {

            songName:"粉刷匠",

            singer:"高金彪"

        }

    ]);

    //        gjbDEManager.removeSong("李白");

    gjbDEManager.removeSong("两只老虎");

    console.log(pwbDEManager.songList);

    console.log(gjbDEManager.songList);

</script>