javascript setInterval不适用于对象 [英] javascript setInterval not working for object

问题描述

所以，我正在尝试创建一个javascript对象，并使用setInterval方法.

SO, I'm trying to create a javascript object, and use the setInterval method.

这似乎不起作用.如果删除引号，则该方法运行一次.有什么想法吗?另外，我正在使用Jquery.

This doesn't seem to be working. If I remove the quotes, then the method runs once. Any ideas why? Also, I'm using Jquery.

<script>
$(function(){
   var kP = new Kompost();
   setInterval('kP.play()', kP.interval);
});

var Kompost = function()
{
   this.interval = 5000;
   var kompost = this;

   this.play = function()
   {
      alert("hello");
   }
}
</script>

推荐答案

像这样调用它:

$(function(){
   var kP = new Kompost();
   setInterval(kP.play, kP.interval);
});

问题在于kP在document.ready处理程序内部，而不在全局上下文中可用(仅在该闭包内部可用).当您将字符串传递给setInterval()或setTimeout()时，它是在全局上下文中执行的.

The problem is that kP is inside that document.ready handler and not available in the global context (it's only available inside that closure). When you pass a string to setInterval() or setTimeout() it's executed in a global context.

如果检查控制台，则会看到错误消息，表示未定义kP，在这种情况下，这是正确的.总体来说，它应该像这样:

If you check your console, you'll see it erroring, saying kP is undefined, which in that context, is correct. Overall it should look like this:

var Kompost = function()
{
   this.interval = 5000;
   var kompost = this;
   this.play = function() {
     alert("hello");
   };
};

$(function(){
   var kP = new Kompost();
   setInterval(kP.play, kP.interval);
});

您可以在这里看到它的工作

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