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SEARCH KEYWORD -- variable name

  Recursive class initialization in Java

When a Java class is referenced and initialized, it has to go through the loading and linking first. Once the loading and linking complete successfully. The class will be initialized. The static variables and constant variables will be initialized during this process. Once the class is initialized, it is ready for use. If when class A is initialized and it is referencing a class B, the class B will also get initialized. But what will happen if class B is referencing class A as well? This is call...

   Java,JVM,class initialization,static final     2015-04-15 21:04:29

  Valid JavaScript variable names

Did you know var π = Math.PI; is syntactically valid JavaScript? I thought this was pretty cool, so I decided to look into which Unicode glyphs are allowed in JavaScript variable names, or identifiers as the ECMAScript specification calls them. Reserved words The ECMAScript 5.1 spec says: An Identifier is an IdentifierName that is not a ReservedWord. The spec describes four groups of reserved words: keywords, future reserved words, null literals and boolean lite...

   JavaScript,Name convention,Standard     2012-02-22 05:16:53

  this in JavaScript in detail

this in JavaScript is always confusing, it is one of the most frequently seen traps in JavaScript. this is not a good design in JavaScript(You can refer some other design flaws of JavaScript here), since it's lazy binding feature, it can be a global object, the current object or.... Some people even avoid using this in JavaScript. Actually if you master how this works, then you will know how to stay away from these traps. Let's take a look at what this points to in below situations. 1. In global...

   JavaScript,this,bind     2013-05-09 18:35:12

  How to Understand and Use nil in Golang Correctly?

In Golang, nil is a predefined identifier that carries different meanings in various contexts, but typically represents "none", "empty" or "zero value". It can be assigned to variables of pointer, slice, map, channel, function, and interface types. Understanding the significance of nil is crucial for writing robust Go programs, as mishandling nil can lead to unexpected issues. nil in Pointers In Go, pointers are a fundamental type that stores the memory address of a variable. When a pointer is d...

   FUNCTION,SLICE,MAP,CHANNEL,GOLANG,NIL     2024-01-05 05:19:40

  What is the use of empty struct in GoLang

In Go, an empty struct struct{} is a struct with no fields that may appear to be of little use, but in reality, it can be useful in certain situations and become a simple and efficient solution in code. As a semaphore or lock Because the empty struct has no fields, it can be conveniently used to implement some concurrency control functions, such as mutex locks, read-write locks. We can use chan struct{} to implement an unbuffered channel for controlling concurrent access. package main import ( ...

   GOLANG,EMPTY STRUCT     2024-04-05 23:54:03

  PHP 7 is coming soon

After a few RCs, PHP 7 will be officially released on November 12, 2015. This is a major release of PHP since PHP 5.6. @Laruence, one of the core contributors of PHP, has posted this news on Weibo(China's Twitter).  This is a one month later than the expected time as recorded in PHP 7 timeline. But it's not that late. The new release will come with a few features including: Scalar type declaration, you can define variable like int now Return type support. Besides declare scalar type ...

   RELEASE DATE,PHP7     2015-11-08 09:13:37

  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

  Writing great JavaScript

I probably could have named this post something like “Writing clean, validating and portable JavaScript”, but that would be no where near as catchy. The problem with “great” is it means different things to different people. I am going to show you my idea of great which may differ from many developers views, but I hope it helps someone improve their code. So what’s the point in this, why can’t you just carry on writing JavaScript as you have been for a...

   JavaScript,Great,Clean,Tips     2012-03-24 05:18:12

  A trick of building multithreaded application on Solaris

Firstly, Let’s see a simple multithreaded application: #include <stdio.h> #include <pthread.h> #include <errno.h> void *thread1_func(void *p_arg) { errno = 0; sleep(3); errno = 1; printf("%s exit, errno is %d\n", (char*)p_arg, errno); } void *thread2_func(void *p_arg) { errno = 0; sleep(5); printf("%s exit, errno is %d\n", (char*)p_arg, errno); } int main(void) { pthread_t t1, t2; ...

   C, Solaris     2014-10-14 02:59:40

  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

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