SEARCH KEYWORD -- function overloading


  var in JavaScript

Geoff published an article sometime ago--"How one missing var ruined our launch". This article described one case where MelonCard uses Node.js as their backend system, suddenly there was a small registration peak period--50-100 people registered concurrently, then the entire website stopped responding and many other strange problems showed up. When they were investigating the source of the problem, they found one missing var in the following code.app.all(‘/apps/:user_id/status’, fun...

   JavaScript,Scope,variable     2012-05-26 12:35:36

  File upload once again

File upload is one of the oldest operation of web design. After 20 years, it's still has no big change, difficult to handle, lack of interaction and poor user experience. Web developers have thought many methods to improve the experience of uploading file in web apps, they developed various plugins based on different JavaScript libraries. However, because of the difference among different web browsers, there is no common interface which makes these plugins work properly or easily on all web brow...

   Web design, File upload, Asynchronous,HTML5     2012-09-02 11:52:21

  How does GoLang know how many CPUs to use?

When running lscpu command on Linux, it will list the CPU info on the machine. Take one example where there is one CPU with 2 cores and each core has two threads which indicates there are 4 cores available. Now let's see how many cores GoLang program would identify. From output, NumCPU and GOMAXPROCS both output 4 which is expected. How does go runtime get this info, does it get it through similar command like lscpu or /proc/cpuinfo? Let's dig more in GoLang's source code. In runtim...

   GOLANG,CPU,NCPU     2020-12-29 23:22:15

  A trick of building multithreaded application on Solaris

Firstly, Let’s see a simple multithreaded application: #include <stdio.h> #include <pthread.h> #include <errno.h> void *thread1_func(void *p_arg) { errno = 0; sleep(3); errno = 1; printf("%s exit, errno is %d\n", (char*)p_arg, errno); } void *thread2_func(void *p_arg) { errno = 0; sleep(5); printf("%s exit, errno is %d\n", (char*)p_arg, errno); } int main(void) { pthread_t t1, t2; ...

   C, Solaris     2014-10-14 02:59:40

  Let browser prompt for storing password when doing AJAX login

In Web 2.0 era, more and more web applications are using AJAX to replace the traditional HTML form element to perform user login. This usually provides a better user experience than form submission. But it also brings a side effect to the end users. That is the browser will not prompt the user whether s/he wants to save the password so that s/he no needs to enter the username/password again when visiting the same site next time. Below is the code snippet which does the AJAX login.  <scri...

   AJAX,Browser,Login,Password     2015-06-04 10:02:46

  JavaScript programming style

Douglas Crockford is a JavaScript expert, he is the inventor of JSON. In November 2011 he made a speech "Youtube", during the speech he talked about what JavaScript programming style is.I recommend this speech to everyone, it not only helps you learn JavaScript but also make you enjoying because Crockford is very humorous and he made audience laugh frequently.Next I will summarize JavaScript programming style according to this speech and his article code convention. The so-called programming ...

   JavaScript, programming style,Curly braces,Equal     2015-10-14 10:16:44

  Undefined property or variable in JavaScript

JavaScript is a weak type language, and also you can use a variable or property where it's undefined. If we don't have correct ways to check whether a property or variable is defined, we may get unexpected results when we try to access the,. How can we check whether a property or variable is undefined? This is actually a somewhat tricky question. Let's start off with some facts about undefined and then see what kind of function is consistent with the ones we care about. JavaScript attaches type...

   Property,Undefined,Array,JavaScript     2014-07-24 06:56:07

  Write Your Own R Packages

Introduction A set of user-defined functions (UDF) or utility functions are helpful to simplify our code and avoid repeating the same typing for daily analysis work. Previously, I saved all my R functions to a single R file. Whenever I want to use them, I can simply source the R file to import all functions. This is a simple but not perfect approach, especially when I want to check the documentation of certain functions. It was quite annoying that you can’t just type ?func&n...

   DATA SCIENCE,R PROGRAMMING,DATA ENGINEERING     2019-10-19 07:20:52

  Mastering Async/Await in JavaScript: A Comprehensive Guide with Examples

As a veteran JavaScript developer, I have seen the evolution of JavaScript's asynchronous programming landscape. From callbacks to promises and now async/await, JavaScript has come a long way in making it easier to handle asynchronous operations in a clean and readable manner. In this article, we will delve into the world of async/await and explore why it has become a popular choice for handling asynchronous operations in JavaScript. We will cover the basics of async/await, its syntax, and how i...

   JAVASCRIPT,COMPARISON,PROMISE,ASYNC AWAIT     2023-02-12 07:26:15

  errGroup in GoLang explained

Today, let's talk about the usage and applicable scenarios of errGroup, which is often used. Why is it useful? Generally, when we use goroutine, we cannot return a value. If you want to pass out the result of the goroutine execution, you usually have to use the channel. The errGroup package is suitable if you want to know when the goroutine you opened encounters an error during execution and stop working, and I need to know the error value. errGroup usage The package needs to be downloaded and i...

   GOLANG,ERRGROUP,WAITHROUP,CONCURRENCY     2023-05-27 23:58:20

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