SEARCH KEYWORD -- EVENT LOOP


  Event Loop Mechanism in JavaScript

Introduction The Event Loop Mechanism The event loop mechanism is the core of how JavaScript handles asynchronous operations. It ensures that the execution order of the code aligns with the expected sequence. JavaScript's Single Thread JavaScript is known for being a single-threaded language, meaning it executes one task at a time. This can lead to a significant issue: if a thread is blocked, the entire program becomes unresponsive. To address this, JavaScript introduced the event loop mechanism...

   JAVASCRIPT,EVENT MECHANISM,EVENT LOOP     2024-07-03 08:19:09

  Some tricks and tips for using for range in GoLang

GoLang provides two major ways to loop through elements of array, slice and map. They are for and for range. Many people find that for range is very convenient when don't care about the index of the element. In this post, some tricks and tips would be talked about regarding for range. 1. Loop and get pointer of each element Assume there is a code snippet like below which is to get the pointer of each element in an array and create a new array with the corresponding pointer. arr := [2]int{1, 2} r...

   POINTER,FOR LOOP,GOLANG,FOR RANGE     2020-03-08 01:07:00

  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

  Highly efficient PHP code writing

Next are some tips for writing highly efficient PHP codes. They are described below: 0. Use single quote to replace double quote, this will be better since PHP will serach for variables in double quoted strings. Note, only echo can do this; 1. If we can define methods of a class as static, then do it. It will increase access speed by 4 times; 2. $row["id"] is 7 times faster than $row[id]; 3. echo is faster than print, and also use echo's multiple parameter format such as echo $str1,$str2 inst...

   PHP,Code writing,High efficient,Tips     2011-07-23 12:35:50

  Fix for-range Issue Again in Go 1.22

With the release of Go 1.22, the Go team addressed a long-standing issue with the for-range loop variable scoping, which had been a common pitfall for developers writing concurrent code. Specifically, the problem was that the loop variable in a for-range loop was reused across iterations, leading to unexpected behavior when closures were involved. The Issue Before Go 1.22 Consider the following example: package forange import "fmt" func Do() { done := make(chan bool) values := []string...

   GO,GO 1.22,FOR RANGE,BUG,GO.MOD     2024-11-21 01:03:04

  The tic-tac-toe game with Python

In this tutorial, we will show how to build a tic-tac-toe game with Python. We will use functions,arrays,if statements,while statements, for loops and error handling etc. First, we need to create two functions, the first function will display the borad of the game: def print_board(): for i in range(0,3): for j in range(0,3): print map[2-i][j], if j != 2: print "|", print "" Here we used two for loops to loop through the map, this map is...

   Python,Tic-Tac-Toe     2013-07-30 02:49:09

  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

  How to use Chome dev tool to find event handler bound to an element

As a front end developer, there is frequent need to debug JS code and sometimes need to find out what event handler has been bound to a HTML element. In this post, we will show how to find out the click event handler bound to a HTML element, this same applies to other events as well. Nowadays, a web application is usually very complicated and there are lots of JS codes which makes it difficult to find out what click event handler has been bound to a HTML element, especially when the JS source co...

   JAVASCRIPT,CHROME,CHROME DEV TOOL,EVENT LISTENER     2019-08-17 22:14:36

  Understanding JavaScript closure and where it can be used

Closure The official definition of closure is: an expression (usually a function) that has many variables and is bound to an environment that includes those variables. In JavaScript, closure refers to the ability of a function to access the lexical scope in which it was defined, even after the function has been executed and left that scope. This ability is due to the fact that when a function is created, it generates a closure that includes a reference to the definition environment of the curr...

   CLOSURE,JAVASCRIPT,USAGE     2023-03-05 02:17:08

  Microsoft to launch Surface Pro 4 on October 6

Microsoft Microsoft has just updated on their website about an event to be held on October 6. This event will be held in New York at October 6 10am EDT.  As described by Microsoft : "We have some exciting news to share about Windows 10 devices". Although there are no details about what these Windows 10 devices are, many think this is the time when new Lumia Phones and Surface Pro 4 will be launched.  The Lumia devices will be Lumia 950 and Lumia 950XL. Both of them will be shipped wit...

   SURFACE PRO 4,MICROSOFT,WINDOWS 10,LUMIA     2015-09-15 07:31:56

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