var Book=function(isbn,title,author){    if (isbn==undefined) throw new Error("不合法");    this.isbn=isbn;    this.title=title||‘无标题‘;    this.author||‘无作者‘;}Book.prototype.display=function(){    ...};

var Book=function(isbn,title,author){    if (!this.checkIsbn(isbn)) throw new Error("ISBN无效");    this.isbn=isbn;    this.title=title||‘无标题‘;    this.author||‘无作者‘;}Book.prototype={    checkIsbn:function(isbn){        if (isbn==undefined||typeof isbn!=‘string‘) {            return false;        }        isbn=isbn.replace(/-/,‘‘);        if (isbn.length!=10 &&isbn.length!=13) {            return false;        }        var sum=0;        if (isbn.length===10) {            if(!isbn.match(/^\d{9}/)){                return false;            }            for(var i=0;i<9;i++){                sum +=isbn.charAt(i)*(10-i);            }            var checksum=sum%11;            if(checksum===10)checksum=‘X‘;            if (isbn.charAt(9)!=checksum) {                return false;            }        }        else{            if(!isbn.match(/^\d{12}/)){                return false;            }            for(var i=0;i<12;i++){                sum+=isbn.charAt(i)*((i%2===0)?1:3);            }            var checksum=sum%10;            if(isbn.charAt(12)!=checksum){                return false;            }        }        return true;    },    display:function(){        ...    }};

var Publication=new Interface(‘Publication‘,[‘getIsbn‘,‘setIsbn‘,‘getTitle‘,‘setTitle‘,‘getAuthor‘,‘setAuthor‘,‘display‘]);var Book=function(isbn,title,author){    this.setIsbn(isbn);    this.setTitle(title);    this.setAuthor(author);}Book.prototype={    checkIsbn:function(isbn){        ...    },    getIsbn:function(){        return this.isbn;    },    setIsbn:function(isbn){        if(!this.checkIsbn(isbn)) throw new Error("ISBN不合法");        this.isbn=isbn;    },    getTitle:function(){        return this.title;    },    setTitle:function(title){        this.title=title||"无标题";    },    getAuthor:function(){        return this.author;    },    setAuthor:function(author){        this.author=author||"无作者";    },    display:function(){        ...    }};

var Book=function(newIsbn,newTitle,newAuthor){    var isbn,title,author;    function checkIsbn(isbn){        ...    }    this.getIsbn=function(){        return isbn;    };    this.setIsbn=function(newIsbn){        if(!checkIsbn(newIsbn)) throw new Error("ISBN不合法");        isbn=newIsbn;    };    this.getTitle=function(){        return title;    };    this.setTitle=function(newTitle){        title=newTitle||‘无标题‘;    };    this.getAuthor=function(){        return author;    };    this.setAuthor=function(newAuthor){        author=newAuthor||‘无作者‘;    };    this.setIsbn(newIsbn);    this.setTitle(newTitle);    this.setAuthor(newAuthor);};Book.prototype={    display:function(){        ...    }};