Question

我对引用变量有一个奇怪的问题。我的设置如下：

var pattern = {/* some object with patterns */};

var view = (new function() {

    this.create_single = function(response) {
        pattern.block // this returns pattern object correctly
    };

    this.create_multi = function(response) {
        pattern.multi_block // this returns pattern as undefined
    };

}());

var data = (new function() {

    this.acquisition = function(response) {
        view.create_single(response);
        view.create_multi(response);
    };

}());

所以在create_multi方法模式变量返回undefined，我没有任何线索为什么会发生这种情况。在Adobe Dreamweaver（我用来编写代码）中，我有一个行错误，上面写着'pattern' used out of scope。谁能帮我理解发生了什么？

感谢您的帮助;）

Answer 1

你的方法没问题，但你的“观察”方法没有任何回报。它适用于以下场景：

var pattern = {
    block: 1,
    multi_block: 2
};

var view = (new function() {

    this.create_single = function(response) {
        return pattern.block // this returns pattern object correctly
    };

    this.create_multi = function(response) {
        return pattern.multi_block // this returns pattern as undefined
    };


}());

Answer 2

尝试没有参数传递

var pattern = {multi_block:"mblock", block:"block" };

var view = ( function() { 
   var create_single = function(response) {
      return pattern.block // this returns pattern object   correctly
   };
   
   var create_multi = function(response) {
    return  pattern.multi_block // this returns pattern as undefined
   };
   return create_single;
}());

console.log(view);

javascript变量undefined（超出范围）

2 个答案: