<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title> New Document </title>
<script type="text/javascript">
var IdCard = function(paperNo){
var validId15=function(){
//alert(paperNo);
return false;
}
var validId18=function(){
//alert(paperNo);
return false;
}
var valid = function (){
if(paperNo.length==15){
return validId15();
}else if(paperNo.length==18){
return validId18();
}
return false;
}
this.validate = {
valueOf: valid,
toString: valid
}
}
function test(){
idCard = new IdCard("123456789012345678");
alert(idCard.validate); //此处打印 false
if(idCard.validate) alert(true); //此处打印 true
}
</script>
</head>
<body>
<input type="button" value="" onclick="test()">
</body>
</html>
if中的idCard.validate没有被执行，为什么？该怎么修改？
