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SEARCH KEYWORD -- Heap memory

  Bug caused by using changeable value as the default in "python method overload"​

In python we can set the passed in parameter's default value to make the function has the same running feature as the method overload in Java. Define a function like this: def testFunction(self, param1, param2=None, param3=None): Normally we use "None" as the parameter's default value. We can also use str/bool as the default value, but is it OK we use empty list [] as its default value? This is our test program: """ A test program using empty list as the passed-in parameter's default value. ...

   PYTHON     2019-03-11 08:52:52

  memcpy() vs memmove() in C

memcpy() copies the bytes of data between memory blocks. If the block of memory overlaps, the function might not work properly. Use memmove() to deal with overlapping memory blocks. memmove() is very much like memcpy() but very flexible as it handles overlapping of memory blocks. example : char msg[50] = "abcdefghijklmnopqrstuvwxyz"; char temp[50]; main() { strcpy(temp, msg); printf("Original Msg = %s\n",temp); memcpy(temp+4, temp+16, 10); printf...

   Memory,memcpy,memmove,C,comparison,diffe     2011-04-14 09:05:10

  Do we need other languages other than C and C++?

There were hundreds of or thousands of programming languages created since the invention of computer. All these languages have the same target which is to make the computer do what we want it do. So we may find that many languages have the same functions, i.e, one task can be completed by one language can be completed by another language as well. Now we may wonder why we need so many different languages. Can we just have C or C++ since they provide the best performance we need. The answer obviou...

   programming language,C,Erlang     2014-06-14 19:39:40

  A Programming Idiom You've Never Heard Of

Here are some sequences of events: Take the rake out of the shed, use it to pile up the leaves in the backyard, then put the rake back in the shed. Fly to Seattle, see the sights, then fly home. Put the key in the door, open it, then take the key out of the door. Wake-up your phone, check the time, then put it back to sleep. See the pattern? You do something, then do something else, then you undo the first thing. Or more accurately, the last step is the inverse of the first. Once you're aware ...

   Programming,Idiom,Strange     2012-01-04 08:12:25

  Are older people better programmers?

Peter Knego states something interesting: “It's official: developers get better with age. And scarcer.”. He uses reputation and other metrics from StackOverflow to corroborate his point. His summary is: Number of coders drops significantly with age. Top developer numbers, at age 27, drop by half every 6-7 years.Developers in their 40s answer roughly twice as much and ask half the questions compared to colleagues in their 20s. It seems younger generation learns and older generatio...

   Programming,Age,Experience,Skill,Advanta     2011-07-28 09:02:23

  Why Dynamic Programming Languages Are Slow

In a statically typed language, the compiler knows the data-type of a variable and how to represent that. In a dynamically-typed language, it has to keep flag describing the actual type of the value of the variable, and the program has to perform a data-dependent branch on that value each time it manipulates a variable.  It also has to look up all methods and operators on it. The knock-on effect of this on branching and data locality is lethal to general purpose runtime performance. T...

   Dynamic language,Slow,Analysis     2012-03-26 15:33:11

  Why can System.out.println be used to exit while loop

Let's first take a look at one simple Java thread code snippet which is supposed to exit the while loop after the first loop run. public class StopThread { private static boolean stopRequested; public static void main(String[] args) throws InterruptedException { Thread backgroundThread = new Thread(new Runnable() { @Override public void run() { int i = 0; while (!stopRequested) { i++; } } }); backgroundThread.start(); TimeUnit.SECONDS.sleep(1); stopRequested = true; } } But the tr...

   JAVA,THREAD,VOLATILE     2018-12-21 19:25:54

  How to check whether a struct implements an interface in GoLang

Unlike other programming languages like Java, when implementing an interface in GoLang, there is no syntax like below to explicit tell the relationship: type I interface { } type A struct implements I { } When looking at the code or running the code in GoLang, it might lead to a case one doesn't know whether a struct implements interface before trying to use it as some interface. According to GoLang spec, as long as a struct implements all functions of an interface, it is considered as having i...

   GOLANG,INTERFACE,IMPLEMENTATION,CHECK     2020-05-03 00:05:54

  Using MemoryMappedBuffer to handle large file in Java

When handling large files, it will largely affect the process speed while using traditional FileInputStream, FileOutputStream or RandomAccessFile since they trigger lots of read and write operations. In Java NIO, a new way of handling large file is introduced which is to use MmeoryMappedBuffer to create memory mapped file. Memory-mapped I/O uses the filesystem to establish a virtual memory mapping from user space directly to the applicable filesystem pages. With a memory-mapped file, you can pre...

   JAVA,IO,NIO     2015-11-13 01:58:08

  Eclipse 4.4 is going to fully support Java 8

Eclipse is the most popular IDE for developing Java applications, but it seems lag behind the Java 8 release a couple of months ago. The current Eclipse is not supporting Java 8 and if you want to run Java 8 programs on it, you need to install a plugin. You can find the plugin at the Eclipse market place. Now Eclipse 4.4 is coming to us on 25th June and the code name for it is Luna. This new version of Eclipse introduces some new features which can ease developer's work, these features includin...

   Eclipse,Luna,Java 8     2014-06-18 05:00:37

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