这是可能的吗,还是我在这里树上错误的树？
var data = 'one';
function fnc(){
this.out = function(){
return data;
}
}
var instance = new fnc();
alert(instance.out);
data = 'two';
alert(instance.out);
// I know that this would achieve that,but that's not what I would like to know.
alert(instance.out());
data = 'two';
alert(instance.out());
更新：
fnc应该表示的对象实际上是Sarissa dom文档.这是一个更精细的版本的fnc(),dom_doc().下面接受的答案已经被整合到下面的功能中.
function get_doc(dom_node) {
var doc;
if (navigator.userAgent.indexOf("MSIE") >= 0) {
doc = new ActiveXObject("Msxml2.DOMDocument.3.0");
doc.loadXML(document.getElementById(dom_node).text);
}
else {
doc = Sarissa.getDomDocument();
doc = (new DOMParser()).parseFromString(document.getElementById(dom_node).textContent,"text/xml");
// runs XSLTProcessor in modern browsers as if it was trasformNode
doc.transformNode = function (stylesheet) {
var processor = new XSLTProcessor();
processor.importStylesheet(stylesheet);
return new XMLSerializer().serializeToString(processor.transformToDocument(this));
}
// allows modern browsers to extract xml the way the legacy IEs did
var getXML = {};
getXML.toString = function(){
return new XMLSerializer().serializeToString(doc);
};
doc.xml = getXML;
}
return doc;
}
演示：JSFIDDLE
解决方法
jsFiddle Demo
这些类型的解决方法真的绕过了惯例.在函数上简单地使用()不应该是那么大的阻碍.使用()是预期的,可读的,最佳实践和行业标准.
不知道为什么smartcaveman决定删除他使用toString的答案,但这是一个可行的方法,虽然有点黑客.
var data = 'one';
function fnc(){
var getData = {};
getData.toString = function(){
return data;
};
this.out = getData;
}
var instance = new fnc();
alert(instance.out);//one
data = 'two';
alert(instance.out);//two
var s = instance.out;
alert(s);//two
