"this"如何进行?语法工作? [英] How does the "this" syntax work?

问题描述

是这行

$(this).attr("id").replace("_button","");

相当于这个吗?

this.attr("id").replace("_button","");

推荐答案

由于this始终包含对object of invocation的引用，所以它实际上取决于在何处调用该代码.

since this always contains a reference to the object of invocation, it really depends where you call that code.

如果在jQuery event handler中调用它，则this是对DOM element本身的引用，因此您需要通过调用$()将其转换为jQuery对象，然后才能对其调用jQuery方法.反过来意味着

If you call this within a jQuery event handler, this is a reference to the DOM element itself, so you need to translate it into a jQuery object by calling $() before you can call jQuery methods on it. That in turn means

this.attr("id").replace("_button","");

在该处无法使用.

例如，如果您要编写一个插件方法，则this已经 IS 一个jQuery object(reference)，并且两行实际上都将执行相同的操作.当然，如果this已经是jQuery object，则您需要做额外的工作，然后尝试再次解析它.

If you're writting a plugin method for instance, this already IS a jQuery object (reference) and both lines would actually do the same. Of course, if this already is a jQuery object you doing extra work, trying to parse it again.

示例:

$.fn.yourplugin = function(){
     // this refers to a jQuery object
     return this.each(function(i,v){
     });
});

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