Question

If I call the killSwitch() outside the onkeypress, I ll cause an error. But inside the onkeypress function, I worked just fine. Why?

www.un.org/Depts/DGACM/index_spanish.htm

// this works fine
var ClassA = function()  
{  
    var doc = document;
// killSwitch();

    doc.onkeypress = function(e){ killSwitch(); }  
    this.killSwitch = function(){ alert( hello world ); }  
}

var myClass = new ClassA();

Answer 1

您可以打上<条码>,因为您将这一方法定义为标的物(<条码>。

您可在<条码>内使用<条码>。

var ClassA = function() {  
    var doc = document, 
              instance = this; // store reference to `this`

    doc.onkeypress = function(e){ instance.killSwitch(); }; 
    this.killSwitch = function(){ alert( hello world ); };
}

var myClass = new ClassA();

Answer 2

Try:

var ClassA = function()  
{  
    var doc = document;
    var killSwitch = function(){ alert( hello world ); };
    killSwitch();

    doc.onkeypress = function(e){ killSwitch(); }  
    this.killSwitch = killSwitch  
}

var myClass = new ClassA();

这样,你就可以界定<条码>技能标准/代码>在<条码>中的功能,从而形成一种封闭状态,并且可以在课内外提供。

友情链接