SEARCH KEYWORD -- WHITEBOARD TEST


  How does computer boot up?

The whole boot process of computer can be summarized in 4 phases. 1. BIOS In the 70's  read-only memory(ROM) was invented. The boot program is written into ROM, the first thing the computer does is to read and execute this program when it's powered on. The program in this chip is called "Basic Input/Output System" (BIOS). 1.1 Power-On Self-Test The BIOS will first check whether the computer hardware can fulfill the basic conditions for booting up, this process is called Power-On Self-Test...

   Computer, boot, partition     2013-02-23 23:19:47

  Install PHP 8 in WampServer

With the release of PHP 8.4, there are some new features added in, it reminds me that I may need to upgrade my development environment PHP version as well. It has php 5.x and php 7.x installed already, now I need to add php 8.x as well. This post will show the steps to achieve this. Step 1 Install PHP 8.x The first step is that we need to download the new PHP version. Here we chose PHP 8.1.31. Once the zip file is downloaded, unzip it and copy the folder to c:/wamp64/bin/php and rename the folde...

   WAMP,GUIDE,PHP VERSION,PHP 8     2024-11-24 02:43:22

  Kodiak PHP can run PHP codes offline on iPad

In the eyes of the vast majority of application developers, iPad is the terminal equipment for running code, rather than the tool used to write code. However, there are some applications developers finding iPad's potential to develop a wide variety of programming applications with some applications, such as Diet Coda, Koder, Gusto and so on. The family of applications for writing applications has added a new member -  Kodiak PHP. This application runs on iPad, it can be used to develop PHP ...

   Kodiak PHP, rogramming,iPad     2012-09-24 11:54:08

  Install multiple versions of Go

As a developer, there might be need in some cases to have multiple versions of Go installed. One may test out some new features of the latest version of Go but also wanna maintain a stable version of Go for daily development purpose. How to maintain multiple versions of Go? The GoLang official website has provided a way to maintain multiple versions of Go by using go get to install the different versions of Go. Below are steps: Download a normal version of Go and install it Go to the Go release...

   MULTIPLE VERSION,GO BINARY,GO VERSION     2021-05-16 02:01:46

  How to prevent next HeartBleed bug?

How to ensure the security of open source projects is a concern for many open source users including individual users and companies. But it's not an easy task to ensure the security of open source projects. Because everyone can see the source code, there is much higher possibility that a bug may be found by someone. Once a bug is disclosed, people may exploit it and do evil things, this may cause loss of money either for individuals or companies, some of the bugs may even have big impact to the...

   Open source,HeartBleed,Security     2014-04-24 09:07:05

  Select top 3 values from each group in a table with SQL

Yesterday, my friend Liu Bing asked me a question about how to select top 3 values for each person in a database table using SQL. I think this question is interesting and it deserves some thoughts. Here I record down how to solve this issue. Assume we have a table which has two columns, one column contains the names of some people and the other column contains some values related to each person. One person can have more than one value. Each value has a numeric type. The question is we want to se...

   SQL,Correlated query,top 3     2013-05-23 03:21:25

  Launch Java process programmatically in Java

In some cases while working on some automation testcase, developers would like to launch Java process programmatically so that the tests can be ran without manual intervention. Java provides such methods to achieve this. ProcessBuilder can be used to build a Java process which can be launched when everything is ready. Basically it can take a list of parameters which are similar to the command line options/arguments.  For example, if you want to launch a Java process, you can do followi...

   JAVA,PROCESSBUILDER,COMMAND LINE     2016-04-27 04:03:30

  Understand Virtual DOM

With the popularity of React, the internals and implementation of Virtual DOM has becoming top discussed topic in tech communities and interviews. This post will give an introduction of Virtual DOM and how to implement a simple Virtual DOM logic. How to understand Virtual DOM In early days, front end developers would update a webpage view based on the data status change(usually after making AJAX call). But it brings performance penalties when there is frequent update as it would cause page reflo...

   JAVASCRIPT,DOM,VIRTUAL DOM     2019-12-07 23:43:04

  How many bytes a boolean value takes in Java?

Have you ever wondered how many bytes a boolean value takes in Java? One byte, this might be the answer comes out of your mind right away. But is it? Let's dig in more. Per Oracle documentation on boolean value definition, there is below statement: boolean: The boolean data type has only two possible values: true and false. Use this data type for simple flags that track true/false conditions. This data type represents one bit of information, but its "size" isn't something that's precisely defin...

   JAVA,INTERVIEW,SIZE,BOOLEAN     2020-02-29 02:49:18

  How to maintain a software project?

For a software engineer, at least from my own experience, maintaining an existing software project would take up a considerable amount of time: adding new features, fixing tricky bugs, and so on. In this post, I will share some some tips about how to become a veteran from a novice quickly when facing a new project. (1) Get familiar with the background knowledge of the project. Every software has its own purposes and users: a device driver serves the specified hardware, whilst a SMS gateway helps...

       2017-08-05 02:20:46

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