SEARCH KEYWORD -- float point


  Why 0.1+0.2 != 0.3

In programming languages such as JavaScript, c/c++, Java and Matlab, you will find that you will get unexpected result when doing float point calculation. For example, when calculating 0.1 + 0.1, you will not get 0.3: > 0.1 + 0.2 == 0.3 false > 0.1 + 0.2 0.30000000000000004 Don't be surprised of this result, this is the end result of IEEE 754 standard, float point number cannot be accurately represented according to IEEE 754 because: No enough memory is allocated for representing the num...

   float point,comparison,JavaScript     2014-11-19 05:32:46

  Why cannot compare double values directly for equality?

A question in PHP: Get some value from the database and use floatval() to convert it to floatint point value, then compare it with another value which is also converted to floating point value with floatval(). These two values are the same when using var_dump() to output, the two outputs are float(8.87), they are the same. But when comparing them for equality, the result is weird., they are not equal. Why?To analyze this question, we need to start with PHP data types. PHP uses weak types. In PHP...

   PHP,floating, precision,compare,equality     2012-06-27 09:01:36

  Data type in MySQL

For both small free database space and large e-commerce websites, reasonable database table structure design is essential. To achieve this, it requires us to have a full understanding of commonly used data types in database system. Below we share some knowledge about data types in MySQL.1. Numeric typesThe numeric types can be classified as : integer, float and decimal type.The so-called "decimal" refers DECIMAL and NUMERIC, they are of the same type. Strictly speaking it is not a numeric type, ...

   MySQL, Data type,VARCHAR     2013-01-01 10:56:06

  It looks like TechCrunch blocks GoDaddy server access

Recently, I encountered an issue with an app I maintain—it suddenly stopped pulling RSS feeds from TechCrunch. At first, I suspected that the RSS feed URL might have changed. However, after further investigation, I discovered a different story. The URL itself was unchanged, but the results varied depending on where the request was coming from. To troubleshoot, I started by setting up a local web server and running a test with my script to see if it could still pull the RSS feed. The script...

   TECH CRUNCH,GODADDY,AI,BLOCK ACCESS     2024-08-17 12:31:52

  Writing Java codes conforming to coding standard

Recently, I was doing some cleanup to one of my current Java project. I find there are many codes which are not conforming to the Java coding standard. So I list them here and hope that people can improve your codes and write maintainable codes. Format source code and manage imports in Eclipse Eclipse provides functions of auto-formatting and imports management, you can use following shortcuts to use these functions. Ctrl+Shift+F --> Format source code Ctrl+Shift+O -- Manage imports an...

   Java, Code standard,Style     2012-09-18 12:50:28

  Hello, Kernel!

When we learn module programming, the first small program must be hello, kernel!. For a novice, how do we avoid some mistakes and how to fix the bugs we have when writing the first module program? Is there any example we can refer to? Here is one example. 1. Write the hello.c 01 #include <linux/init.h> 02 #include <linux/module.h> 03 #include <linux/kernel.h> 04 //Compulsory 05 //Module lincese declaration 06 MODULE_LICENSE("GPL"); ...

   module,kernel,Linux     2013-05-03 03:33:52

  Install Open webOS on Linux

HP has just released its first beta version of the webOS, It is said the user experience of webOS is quite impressive, so I immediately had it installed on my PC. There are two versions of Beta release,one embedded version and one Ubuntu version. I briefly share my installation experience of webOS in Linux. In the official document, it says "By 'Linux' we mean 'Ubuntu Linux'", it doesn't support server version and 64 bit version of Ubuntu. Here I use Mint 13. 1. Clone source code from github Add...

   Linux,webOS,Ubuntu,embedded,HP     2012-09-10 19:36:30

  Why no max/min function for integer in GoLang

You may notice that there is no max/min function provided to compare the maximum/minimum of two or more integers if you are a GoLang developer with some experience . In other languages, these functions are provided as part of the core lib functions. Have you wondered why?  Indeed GoLang provides max/min function in math package, but they are used for comparing float64 data type. The signature of these two functions are math.Min(float64, float64) float64 math.Max(float64, float64) float...

   GOLANG,MAX,INT,INT64     2019-06-08 07:00:55

  Ways to make elements in HTML center aligned horizontally

In our daily HTML design,  it is an easy job to horizontally center align an element with known width. <div class="element">I am<a href="http://www.aiubug.com" target="_blank" rel="external" title=""> bug </a>！</div>  .element{width:960px;margin:0 auto;}  The above codes set the width of the div block and horizontally center align it. It's very easy to implement. However, if we have some elements we don;t know their width and we still want to...

   HTML,CSS,Center align,Unknown width     2012-07-11 12:55:00

  When will resizing be triggered in Java HashMap?

HashMap is one of the most frequently used collection types in Java, it stores key-value pairs. Ideally it expects to use hash table which expects the data access time complexity to be O(1), however, due to hash conflicts, in reality, it uses linked list or red-black tree to store data which makes the worst case time complexity to be O(logn).  Although collections are using data structures like arrays and linked lists, unlike arrays, they will dynamically resize when there is not enough spa...

   JAVA,RESIZE,HASHMAP,THRESHOLD     2020-05-02 20:41:19

RECENT