在 JavaScript 中处理异步和回调就是家常便饭,我们通常会面对这样一些问题:
1. 如何优雅滴组织我们的回调代码
2. 对异步函数错误处理的最佳实践是什么
3. 异步嵌套问题
4. 怎样使我们的代码可读性和可维护性更高
Programs are meant to be read by humans and only incidentally for computers to execute. 程序是给人读的,只是顺带让计算机执行一下。 ——《编写可维护的JavaScript》@Donald Knuth
当然,最常见也是最简单的处理方式就是,直接将回调函数或错误处理函数作为异步函数的参数,在异步函数返回时进行相应的调用,这继续阅读 »
How To Use the Widget Factory
To start, we'll create a progress bar that just lets us set the progress once. As we can see below, this is done by calling jQuery.widget() with two parameters: the name of the plugin to create, and an object literal containing functions to support our plugin. When our plugin gets called,继续阅读 »
QNAN wiki上是这样说的:
A QNaN is a NaN with the most significant fraction bit set. QNaN’s propagate freely through most arithmetic operations. These values pop out of an operation when the result is not mathematically defined. (details)[http://en.wikipedia.org/wiki/NaN]
我尝试过sqrt(-1), 1/0, NAN/NAN都不行
结果:继续阅读 »
今天突然想用markdown写博文,这样应该会方便不少。
开工
1.下载插件。
这里我选择了Markdown QuickTags
在官网看到
!This plugin hasn't been updated in over 2 years. It may no longer be maintained or supported and may have compatibility issues when used with more recent versions of WordPress.
有点被惊呆
2.启用插件
下载完该插件之后,放入WordPress的plugins文件夹下,上传代码,然后再后台启用即继续阅读 »
(This post is rewritten to adapt to the latest release of pipeR)
Pipeline is receiving increasing attention in R community these days. It is hard to tell when it begins but more people start to use it since the easy-and-fast dplyr package imports the magic operator %>% from magrittr, the pioneer package of pipeline op继续阅读 »