JS学习笔记:Javascript类的继承


JavaScript中类的学习,从基本类继承过来方法

也可以这样实现:

Java代码

function newClass(){   
     this.firstName="frank";   
     this.toUc=String.toUpperCase;   
     this.toString=function(){   
        return this.toUc(this.firstName);   
     }   
 }   
 var nc=new newClass();   
 alert(nc);//在IE中没反应。。  
   function newClass(){
        this.firstName="frank";
        this.toUc=String.toUpperCase;
        this.toString=function(){
           return this.toUc(this.firstName);
        }
    }
    var nc=new newClass();
    alert(nc);//在IE中没反应。。

一个简单的客户端验证

Java代码

<html>   
<head>   
  <title>javascript</title>   
    <script type="text/javascript">   
        function doSubmit(inForm){   
            if(inForm.firstName.value==""){   
                alert("firstName is null");   
                return false;   
            }   
            if(inForm.lastName.value ==""){   
                alert("lastName is null");   
            }   
            inForm.submit();   
            return true;   
        }   
    </script>   
</head>   
<body>   
<form action="#" name="test" method="post">   
    First name: <input type="text" name="firstName">   
    <br>   
    Last name:<input type="text" name="lastName">   
    <br>   
    <input type="button" value="submit" onclick="doSubmit(this.form);">   
</form>   
</body>   
</html>   
</form>  
<html>
<head>
  <title>javascript</title>
    <script type="text/javascript">
        function doSubmit(inForm){
            if(inForm.firstName.value==""){
                alert("firstName is null");
                return false;
            }
            if(inForm.lastName.value ==""){
                alert("lastName is null");
            }
            inForm.submit();
            return true;
        }
    </script>
</head>
<body>
<form action="#" name="test" method="post">
    First name: <input type="text" name="firstName">
    <br>
    Last name:<input type="text" name="lastName">
    <br>
    <input type="button" value="submit" onclick="doSubmit(this.form);">
</form>
</body>
</html>
</form>

一般这样写

Java代码

<form action="#" name="test" method="post" onSubmit="return doSubmit(this);">   
    First name: <input type="text" name="firstName">   
    <br>   
    Last name:<input type="text" name="lastName">   
    <br>   
    <input type="button" value="submit" >  


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