SEARCH KEYWORD -- MATH.MAX()



  Understanding the "this" keyword in JavaScript

Many people get tripped up by the this keyword in JavaScript. I think the confusion comes from people reasonably expecting this to work like “this” does in Java or the way people use “self” in Python. Although this is sometimes used to similar effect, it’s nothing like “this” in Java or other languages. And while it’s a little harder to understand, its behavior isn’t magic. In fact, this follows a relatively small set of simple rules. This...

   JavaScript,this,understanding     2012-03-29 13:48:59

  Use Java ThreadLocal with caution

According to Oracle documentation, ThreadLocal is a class provides thread-local variables. These variables differ from their normal counterparts in that each thread that accesses one (via its get or set method) has its own, independently initialized copy of the variable. ThreadLocal instances are typically private static fields in classes that wish to associate state with a thread. In short, ThreadLocal variables are variables belong to a thread, not a class or an instance of a class. One common...

   JAVA,MEMORY LEAK, THREADLOCAL     2015-11-03 07:31:57

  SOME LESSONS LEARNED

Note: Google was kind enough to invite me to give a short talk at their Zeitgeist conference earlier this week. It was a really interesting conference and I got a chance to meet a lot of people I admire. For my talk, I decided to use material from some of my blog posts over the years that I thought might appeal to a broader audience. Unfortunately, I was still recovering from a nastly cold/flu so I didn’t deliver the talk as well as I’d like.  Below is the text.Today, I wanted...

   Investor,Startup,Lesson,Experience,Investment     2011-10-12 11:47:02

  Speed Hashing

A given hash uniquely represents a file, or any arbitrary collection of data. At least in theory. This is a 128-bit MD5 hash you're looking at above, so it can represent at most 2128 unique items, or 340 trillion trillion trillion. In reality the usable space is substantially less; you can start seeing significant collisions once you've filled half the space, but half of an impossibly large number is still impossibly large. Back in 2005, I wondered about the difference between a checksum and...

   Speed hashing,Security,MD5     2012-04-07 10:35:15

  String.length() vs String.getBytes().length in Java

In Java, String.length() is to return the number of characters in the string, while String.getBytes().length is to return the number of bytes to represent the string with the specified encoding. By default, the encoding will be the value of system property file.encoding, the encoding name can be set manually as well by calling System.setProperty("file.encoding", "XXX"). For example, UTF-8, Cp1252. In many cases, String.length() will return the same value as String.getBytes().length, but in some ...

   Java,UTF8,String,Encoding,Sample     2015-04-01 22:22:23

  JavaScript as a First Language

At Khan Academy we've been investigating teaching Computer Science to students in some new and interesting ways. The most interesting aspect of which is that we're likely going to be teaching them JavaScript as their first language. We're in a very unique position as we're primarily aiming to teach students who've been through our previous math and science-centric curriculum. Because of this we can create some rather compelling exercises and projects that never would've been feasible other...

   JavaScript,Learning,First language,Inheritence,Prototype     2011-12-23 07:53:45

  Learning Server-Side JavaScript with Node.js

Node.js is all the buzz at the moment, and makes creating high performance, real-time web applications easy. It allows JavaScript to be used end to end, both on the server and on the client. This tutorial will walk you through the installation of Node and your first “Hello World” program, to building a scalable streaming Twitter server.What is Node.js?JavaScript has traditionally only run in the web browser, but recently there has been considerable interest in bringing it to the...

   JavaScript,Server side,Node.js.Implement     2011-09-20 13:33:15

  php://input in PHP

When using xml-rpc, server side will get the data from client with php://input method instead of $_POST. Hence today we will discuss php://input. PHP official manual has below explanation to php://input: “php://input allows you to read raw POST data. It is a less memory intensive alternative to $HTTP_RAW_POST_DATA and does not need any special php.ini directives. php://input is not available with enctype=”multipart/form-data”. Here we und...

   php://input, IO, input     2013-02-25 20:43:00

  How much money do you *really* need to start your company?

I keep hearing startup entrepreneurs tell me “We need funding. If we just had $XXXk of investment, we’d be killing it right now.” I press them with one question: what would you do with the money if you had it? Inevitably the question is met with a blank stare. Most of the time people haven’t thought about it. The answers that do come feel a little half-baked:“Buy a bunch of ad words to get people to our site – that’s all we need”“Build th...

   Business,Startup,Investment,Money,Ad     2011-09-26 11:16:35

  Great code is written twice (or more)

The last couple of years more and more people have been moving towards Agile development. These techniques aren’t new, most we’re devised in the 80s or 90s. But finally these days programmers and (more importantly) business consultants, architects and clients have learned to love and embrace Agile development.Evolving requirementsIt has now become common knowledge that you can’t write down all the requirements before you start the project. These requirements h...

   Twice,Good code,Recoding,Agile,Evolvement     2011-11-01 00:36:35