根据 jQuery Events: Stop (Mis)Using Return False(存档链接)，调用时返回false执行三个任务:

According to jQuery Events: Stop (Mis)Using Return False (archived link), returning false performs three tasks when called:

1. event.preventDefault();
2. event.stopPropagation();
3. 停止回调执行并在调用时立即返回.

取消默认行为所需的唯一操作是preventDefault().发出 return false; 可以创建脆弱的代码.通常你只想要这个:

The only action needed to cancel the default behaviour is preventDefault(). Issuing return false; can create brittle code. Usually you'd want just this:

$("a").on( 'click', function (e) {
    // e == our event data
    e.preventDefault();
});

其次this"是javascript中的DOM元素，$(this)"是jQuery元素引用 DOM 元素.在 jQuery's this: demystified 阅读有关该主题的更多信息.

And secondly "this" is a DOM element in javascript and "$(this)" is a jQuery element that references the DOM element. Read more on the topic at jQuery's this: demystified.