欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  web前端

return false;和e.preventDefault();的区别_javascript技巧

程序员文章站 2022-05-16 12:08:01
...
Have you ever seen those two things (in the title) being used in jQuery? Here is a simple example:
复制代码 代码如下:

$("a").click(function() {
$("body").append($(this).attr("href"));
return false;
}

That code would append the href attribute as text to the body every time a link was clicked but not actually go to that link. The return false; part of that code prevents the browser from performing the default action for that link. That exact thing could be written like this:
复制代码 代码如下:

$("a").click(function(e) {
$("body").append($(this).attr("href"));
e.preventDefault();
}

So what's the difference?


The difference is that return false; takes things a bit further in that it also prevents that event from propagating (or “bubbling up”) the DOM. The you-may-not-know-this bit is that whenever an event happens on an element, that event is triggered on every single parent element as well. So let's say you have a box inside a box. Both boxes have click events on them. Click on the inner box, a click will trigger on the outer box too, unless you prevent propagation. Like this:
return false;和e.preventDefault();的区别_javascript技巧
演示地址:http://css-tricks.com/examples/ReturnFalse/
So in other words:
复制代码 代码如下:

function() {
return false;
}

// IS EQUAL TO

function(e) {
e.preventDefault();
e.stopPropagation();
}

It's all probably a lot more complicated than this and articles like this probably explain it all a lot better.


参考:

1.The difference between ‘return false;' and ‘e.preventDefault();'
2.Event order

测试代码打包下载