SEARCH KEYWORD -- One line


  Understand JavaScript prototype

For an front end programming language like JavaScript, if we want to understand its OOP feature, we need to understand its objects, prototype chain, execution context, closure and this keyword in deep. If you have a good understanding on these concepts, you should be confident that you can handle this language well. The inheritance in JavaScript is not class inheritance like Java, but it adopts another mechanism-- prototype inheritance. The key to prototype inheritance is the prototype chain mec...

   JavaScript, prototype, __proto__     2013-02-02 02:34:09

  Capture video stream with WebRTC

WebRTC(Web Real-Time Communication) is an API supporting real time audio and video communication through a browser. It is now a recommended W3C standard. This post is to show you how to capture video stream and screenshot with WebRTC. Capture video stream To play video stream from the video camera, we first need to put a video tag in our code: <video id="video"></video> The main function to get the video stream is the navigator.getUserMedia, as of now only few of the browsers support...

   WebRTC,Video,Screenshot     2013-10-24 21:04:41

  Android IDE gets Pie-Friendly Update

An integrated development environment (IDE) provides facilities to computer programmers for software development. It consists of a source code editor, builds automation tools, and a debugger. The aim of the IDE is to reduce the configuration necessary to piece together multiple development utilities.The android application development process has become easier with the advancement of the new technologies. There are many considerations that are taken into account before developing an application....

       2018-09-26 07:41:56

  Stub Mixlib::ShellOut and shell_out in Ruby unit testing

Unit testing is part of software development to ensure the tiny component of a function can work as designed. Different frameworks and tools can be used to run unit testing for different programming languages. In Ruby, one popular unit testing framework is Rspec, or Chefspec if you are writing Chef recipes. While writing Chef recipes, some low level commands(DOS commands or shell commands) need to be executed on the managed resource to perform actions or gather information. For example, lis...

   RUBY,UNIT TESTING,RSPEC,CHEFSPEC,SHELL_OUT     2016-11-11 00:14:46

  Shortcut keys in Sublime Text 3(Animated demo)

Sublime Text 3 is a light weight code editor which supports lots of languages. It has lots of shortcuts and plugins easing work of programmers. In this post, we will introduce some shortcuts supported in Sublime Text 3 and show how powerful they are. 1. Select sibling matching(equal) word (Ctrl + D) Put the cursor on one word, press Ctrl + D to select the word, then press Ctrl and following by pressing D, it will select next matching word. The number of Ds pressed will mean number of matching wo...

   TIPS,SHORTCUT KEY,SUBLIME TEXT     2016-04-28 02:41:28

  Three images to understand immutability of String in Java

String is immutable in Java. This means once a String object is created and instantiated, that object cannot be changed. Any operation on the String object will create a new Object instead of operating on the original content. Below are three images to help you understand String immutability in Java. Declare a String String s = "abcd"; s stores the reference to the string content created in the heap. Assign the String reference to another String variable String s2 = s; s2 stores the same ...

   STRING,JAVA     2016-03-11 20:58:28

  Workaround size limit of phpMyAdmin import sql file

When doing website development with MySQL, we often need to do database backup and restore. For website, the data in database will grow quickly, so when we back up the database, the size of the generated sql file may be over 80MB which is the max allowed size when we want to import a sql file for restoring our database using phpMyAdmin. To workaround this limit, we need to review the documentation of phpMyAdmin. Fortunately, I found an online article written by David Pratt  which gave us a ...

   MySQL,phpMySQLAdmin,80M,import,solution,limit     2014-08-14 09:59:27

  Using keytool to create certificate chain

JDK provides a command line tool -- keytool to handle key and certificate generation. This tool has a set of options which can be used to generate keys, create certificates, import keys, install certificate and export certificates etc. In this tutorial, we will show how to create certificate chain using keytool. If you want to understand how to create certificate chain programmably, please refer to Generate certificate in Java -- Certificate chain. To begin, we first generate a key pair whi...

   JAVA,KEYTOOL,CERTIFICATE CHAIN,CERTIFICATE     2015-12-17 07:09:33

  A trap about PHP random number

The method to get random number in PHP is very simple, we only need to use rand() function. int rand ( int $min , int $max ) One function call can return the random number in a specified range. But in fact, the random number in computer is actually pseudorandomness, generally to increase the randomness, we may set a random seed before calling rand(). void srand ([ int $seed ] ) According to other language features, we should pass a time value as a parameter to the srand() function, generally...

   PHP,rand,srand,mt_rand     2013-06-07 09:10:10

  Android create button tutorial

This tutorial assumes that you already have an activity and are using an XML layout. Open the layout XML and add the button element.  Assign an ID with the “@+id” operator.  The + tells Android to generate an ID for this element so that you can reference it in your Java files. This is an example. Your layout and text elements will probably be very different. In this example case, the ID of the button is “close”. <Button android:id="@+id/close" android:lay...

   Android,Simulator,Button,XML,Tutorial     2014-11-07 08:30:10

RECENT