Javascript跟踪变量更改 [英] Javascript Track Variable Change

问题描述

是否有可能跟踪javascript中的变量更改？我希望能够在类中变量发生变化时启动函数。

 < script> 
 var mywindow = new Box（）; 
 mywindow.title =newtitle; 
 //启动mywindow.applyTitle（）并更改html 
< / script> 
  

解决方案

您可以使用明确的方法来设置值并附上你的回调。有些东西可以工作：
$ b $ pre $ var Box = new Class（{
setTitle：function（title）{
this.title = title;

//现在调用你的回调函数，你可能需要一些方法来注册它们btw

}）;


改变想法以适合您的类语法...

JS的getter / setter语法也不太好（相当于Python中的属性）。请参阅 http://ejohn.org/blog/javascript-getters-and-setters/ 。

Is it possible to track a variable change in javascript? I would like to be able to launch a function when a variable has been changed in a class.

<script>
var mywindow = new Box();
mywindow.title = "newtitle"; 
//Launches mywindow.applyTitle() and changes html
</script>

解决方案

You could probably use an explicit method for setting the value and attach your callbacks to that. Something along this would work:

var Box = new Class({
    setTitle: function(title) {
        this.title = title;

        // call your callbacks now. you probably need some way to register them btw
    }
});

Adapt the idea to fit your class syntax...

There is also a not so well supported getter/setter syntax for JS (equivalent to properties in Python). See http://ejohn.org/blog/javascript-getters-and-setters/ .

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