js初始化验证实例详解
本文实例讲述了js初始化验证的方法。分享给大家供大家参考，具体如下：
<scripttype="text/javascript">
varBook=function(isbn,title,author){
if(!this.checkIsbn(isbn)){
thrownewError('Book:InvalidISBN.');
}
this.isbn=isbn;
this.title=title||'Notitlespecified';
this.author=author||'Noauthorspecified';
}
Book.prototype={
checkIsbn:function(isbn){
if(isbn==undefined||typeofisbn!='string'){
returnfalse;
}
returntrue;//Alltestspassed.
},
display:function(){
alert("isbn:"+this.isbn+"title:"+this.title+"author:"+this.author);
}
};
vartheHobbit=newBook('0-395-07122-4','TheHobbit','J.R.R.Tolkein');
theHobbit.display();//OutputsthedatabycreatingandpopulatinganHTMLelement.
</script>
对isbn进行验证。是否定义，是否为字符串等等。对title进行判断，设置默认。
另一种实现方式
<scripttype="text/javascript">
/*出版interface.*/
/*varPublication=newInterface('Publication',['getIsbn','setIsbn','getTitle',
'setTitle','getAuthor','setAuthor','display']);*/
varBook=function(isbn,title,author){//implementsPublication
this.setIsbn(isbn);
this.setTitle(title);
this.setAuthor(author);
}
Book.prototype={
checkIsbn:function(isbn){
if(isbn==undefined||typeofisbn!='string'){
returnfalse;
}
returntrue;//Alltestspassed.
},
getIsbn:function(){
returnthis.isbn;
},
setIsbn:function(isbn){
if(!this.checkIsbn(isbn))thrownewError('Book:InvalidISBN.');
this.isbn=isbn;
},
getTitle:function(){
returnthis.title;
},
setTitle:function(title){
this.title=title||'Notitlespecified';
},
getAuthor:function(){
returnthis.author;
},
setAuthor:function(author){
this.author=author||'Noauthorspecified';
},
display:function(){
alert("isbn:"+this.isbn+"title:"+this.title+"author:"+this.author);
}
};
vartheHobbit=newBook('0-395-07122-4','','J.R.R.Tolkein');
theHobbit.display();//OutputsthedatabycreatingandpopulatinganHTMLelement.
</script>
接口实现，参考接口，定义了好多方法。
内部方法命名加_，例如这个检测的方法_checkIsbn
<scripttype="text/javascript">
/*出版interface.*/
/*varPublication=newInterface('Publication',['getIsbn','setIsbn','getTitle',
'setTitle','getAuthor','setAuthor','display']);*/
varBook=function(isbn,title,author){//implementsPublication
this.setIsbn(isbn);
this.setTitle(title);
this.setAuthor(author);
}
Book.prototype={
_checkIsbn:function(isbn){
if(isbn==undefined||typeofisbn!='string'){
returnfalse;
}
returntrue;//Alltestspassed.
},
getIsbn:function(){
returnthis.isbn;
},
setIsbn:function(isbn){
if(!this._checkIsbn(isbn))thrownewError('Book:InvalidISBN.');
this.isbn=isbn;
},
getTitle:function(){
returnthis.title;
},
setTitle:function(title){
this.title=title||'Notitlespecified';
},
getAuthor:function(){
returnthis.author;
},
setAuthor:function(author){
this.author=author||'Noauthorspecified';
},
display:function(){
alert("isbn:"+this.isbn+"title:"+this.title+"author:"+this.author);
}
};
//vartheHobbit=newBook(123,'','J.R.R.Tolkein');//非字符串抛出异常
vartheHobbit=newBook('1990-78sd-1092','','J.R.R.Tolkein');
theHobbit.display();//OutputsthedatabycreatingandpopulatinganHTMLelement.
</script>
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