js初始化验证实例详解
编程学习 2021-07-04 19:19www.dzhlxh.cn编程入门
这篇文章主要介绍了js初始化验证,结合实例形式分析了javascript初始化验证相关的判断、设置、检测等相关操作技巧,需要的朋友可以参考下
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：
<script type="text/javascript">
var Book = function(isbn, title, author) {
if(!this.checkIsbn(isbn)){
throw new Error('Book: Invalid ISBN.');
}
this.isbn = isbn;
this.title = title || 'No title specified';
this.author = author || 'No author specified';
}
Book.prototype = {
checkIsbn: function(isbn) {
if(isbn == undefined || typeof isbn != 'string') {
return false;
}
return true; // All tests passed.
},
display: function() {
alert("isbn:"+this.isbn+" title:"+this.title+" author:"+this.author);
}
};
var theHobbit = new Book('0-395-07122-4', 'The Hobbit', 'J. R. R. Tolkein');
theHobbit.display(); // Outputs the data by creating and populating an HTML element.
</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
<script type="text/javascript">
/* 出版 interface. */
/* var Publication = new Interface('Publication', ['getIsbn', 'setIsbn', 'getTitle',
'setTitle', 'getAuthor', 'setAuthor', 'display']); */
var Book = function(isbn, title, author) { // implements Publication
this.setIsbn(isbn);
this.setTitle(title);
this.setAuthor(author);
}
Book.prototype = {
checkIsbn: function(isbn) {
if(isbn == undefined || typeof isbn != 'string') {
return false;
}
return true; // All tests passed.
},
getIsbn: function() {
return this.isbn;
},
setIsbn: function(isbn) {
if(!this.checkIsbn(isbn)) throw new Error('Book: Invalid ISBN.');
this.isbn = isbn;
},
getTitle: function() {
return this.title;
},
setTitle: function(title) {
this.title = title || 'No title specified';
},
getAuthor: function() {
return this.author;
},
setAuthor: function(author) {
this.author = author || 'No author specified';
},
display: function() {
alert("isbn:"+this.isbn+" title:"+this.title+" author:"+this.author);
}
};
var theHobbit = new Book('0-395-07122-4', '', 'J. R. R. Tolkein');
theHobbit.display(); // Outputs the data by creating and populating an HTML element.
</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
<script type="text/javascript">
/* 出版 interface. */
/* var Publication = new Interface('Publication', ['getIsbn', 'setIsbn', 'getTitle',
'setTitle', 'getAuthor', 'setAuthor', 'display']); */
var Book = function(isbn, title, author) { // implements Publication
this.setIsbn(isbn);
this.setTitle(title);
this.setAuthor(author);
}
Book.prototype = {
_checkIsbn: function(isbn) {
if(isbn == undefined || typeof isbn != 'string') {
return false;
}
return true; // All tests passed.
},
getIsbn: function() {
return this.isbn;
},
setIsbn: function(isbn) {
if(!this._checkIsbn(isbn)) throw new Error('Book: Invalid ISBN.');
this.isbn = isbn;
},
getTitle: function() {
return this.title;
},
setTitle: function(title) {
this.title = title || 'No title specified';
},
getAuthor: function() {
return this.author;
},
setAuthor: function(author) {
this.author = author || 'No author specified';
},
display: function() {
alert("isbn:"+this.isbn+" title:"+this.title+" author:"+this.author);
}
};
//var theHobbit = new Book(123, '', 'J. R. R. Tolkein'); // 非字符串抛出异常
var theHobbit = new Book('1990-78sd-1092', '', 'J. R. R. Tolkein');
theHobbit.display(); // Outputs the data by creating and populating an HTML element.
</script>
更多关于JavaScript相关内容可查看本站专题：《》、《》、《》、《》、《》、《》、《》、《》及《》
希望本文所述对大家JavaScript程序设计有所帮助。