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  Do you have this kind of comments in your source code?

Writing runnable code is the essential skill of a programmer, writing understandable comment is also a skill a programmer should acquire. There is some famous saying that bad comment is worth than no comment. Usually your code will be maintained by other people, if you provide them some difficult to understand or misguided comments, this will be nightmare to them. While at some other time, programmers may put some funny comments in their codes which may make others laugh. Today we...

   COMMENT,HUMOR     2016-08-01 10:25:14

  Error handling style in C

Following are three error handling styles in C.Which one you like the most? Or you don't like any one?1. /* Problem : Not enough. Easy to be wrong */int foo(int bar){        int return_value = 0;        int doing_okay = 1;        doing_okay = do_something( bar );        if (doing_okay)        { ...

   C,Error handling style,Goto,Nested if     2012-04-24 06:51:00

  How to check a port is taken by which program on Linux

Lots of you may have encountered some error message stating that the port has been taken by another program while trying to start a program on Linux. And you would want to know which program takes the port you want to use. This post will provide some feasible ways to check out which program is taking a specific port. lsof -i:[port] lsof is the command to list open files on Linux. And if you know more about Linux you should get to know everything on Linux is a file even including networ...

   LINUX,PORT,NETSTAT,LSOF     2018-08-12 04:27:57

  How to draw pentagram in HTML5 canvas

I wrote simple function to this magical symbol I like so much: 123456789101112131415161718192021222324252627282930<!doctype html><html><body>    <canvas id="c" width="500" height="500"></canvas>    <script> var ctx = (document.getElementById("c")).getContext("2d"); // draws rotated pentagram with or without cirlefunction pentagram( ctx, x, y, radius, rotate, circle ){    ctx.beginPath();&nbs...

   Html 5,Canvas,pentagram     2012-04-23 12:56:06

  How the Go language improves expressiveness without sacrificing runtime performance

This week there was a discussion on the golang-nuts mailing list about an idiomatic way to update a slice of structs. For example, consider this struct representing a set of counters. type E struct { A, B, C, D int } var e = make([]E, 1000) Updating these counters may take the form for i := range e { e[i].A += 1 e[i].B += 2 e[i].C += 3 e[i].D += 4 } Which is good idiomatic Go code. It's pretty fast too BenchmarkManual 500000 ...

   Go,Expressiveness,Performace,Sacrifice     2012-02-12 04:53:55

  Reducing Code Nesting

"This guy’s code sucks!" It’s something we’ve all said or thought when we run into code we don’t like. Sometimes it’s because it’s buggy, sometimes it’s because it conforms to a style we don’t like, and sometimes it’s because it just feels wrong. Recently I found myself thinking this, and automatically jumping to the conclusion that the developer who wrote it was a novice. The code had a distinct property that I dislike: lots of ...

   Code nesting,Readability,Maintainability,Reduction     2012-01-02 08:13:46

  Handle ”cannot modify header information – headers already sent by”

Man PHP developers should encounter ”Warning: Cannot modify header information – headers already sent by ….” error before when executing a PHP script. Here are some solutions to this error. 1. Blank line Check whether there is any blank line after , especially in the files which are used in include() and require(0, some problems are caused by blank lines. 2. Add exit() after head() header (“Location: xxx”); exit(); 3. Use output cache <?php ob_start(); ...

   header sent, PHP error handle     2012-11-17 08:45:22

  do {...} while (0) in macros

If you are a C programmer, you must be familiar with macros. They are powerful and can help you ease your work if used correctly. However, if you don't define macros carefully, they may bite you and drive you crazy. In many C programs, you may see a special macro definition which may seem not so straightforward. Here is one example: #define __set_task_state(tsk, state_value) \ do { (tsk)->state = (state_value); } while (0) There are many this kind of macros which uses do{...}while(0)...

   C,macro,C++     2014-01-23 07:16:13

  jsonSerialize() in extended class

Since PHP 5.4.0, there is a convenient interface JsonSerializable which can be used to indicate that a PHP object can be serialized to JSON object. It has only one method which should be implemented by any class which implements this interface. The method is named jsonSerialize(). It's really easy to serialize an object to JSON object. Here is one example: <?php class ArrayValue implements JsonSerializable { public function __construct(array $array) { $this->array = $array; ...

   JSON,jsonSerialize,Inheritance,extends     2014-07-26 05:54:00

  How Many C Programs Are There?

If I choose a size S, can you tell me how many valid C programs exist that are no larger than that size? I’m actually interested in the answer — it’ll help me make a point in a paper I’m writing. Shockingly, the Internet (or at least, the part of it that I looked at based on a few searches) does not provide a good answer. Let’s start with a few premises: Since it would be exceedingly difficult to construct the exact answer, we’re looking for a respe...

   C Progra,Number,Statistic,Calculation     2012-02-22 05:18:32