SEARCH KEYWORD -- EVENT LOOP


  PHP to get long running process progress dynamically

Frequently in web applications, we may have a request to the back end system which may trigger a long running process such as searching huge amount of data or a long running database process. Then the front end webpage may hang and wait for the process to be finished. During this process, if we can provide the user some information about the progress of the back end process, it may improve user experience. Unfortunately, in web applications, this seems not an easy task because web scripting lang...

   AJAX,PHP,progress,long process,demo     2012-06-04 07:29:37

  Macro to change text color conditionally in Excel

Macros are small but very powerful VBA programs in Microsoft Office software. They can help us complete some repeated tasks automatically. Today, I will show you one macro example which is to change the text color conditionally. The excel file has a work sheet which contains some records of request. I want to check the status of each request, if the status of a request is approved, the text color of the status should be green; if the status of a request is rejected, the text color of the status ...

   Macro,Excel,Text color,Conditionally     2012-07-07 12:53:28

  Implementation of +,-,*,/ with bitwise operator

There is a question asked on Stackoverflow : Divide a number by 3 without using *,/,+,-,% operators. This question is an Oracle interview question. Some people give excellent answers. You can go there and take a look. Usually we need to use bitwise operators to do this kind of implementations. Here I want to show you ways to implement +,-,*,/ with bitwise operators. A bitwise operation operates on one or more bit patterns or binary numerals at the level of their individual bits. It is a fast, pr...

   Bitwise operator,Shift,Add,Subtract,Multiplication,Division     2012-08-05 01:52:47

  Ensure triggering transitionend event in JavaScript

CSS3 Transition has been widely used in modern web app development to offer users animations. Traditionally animations of element in HTML are controlled by JavaScript. If fancy animation is desired, then third party plugins can be installed in browsers such as Flash, Silverlight, Java Applet etc. With CSS3, animations can be easily achieved like a charm. Transition is one of the many features provided by CSS3. It can be used to transit one element from one state to another state smoothly within ...

   CSS3 TRANSITION, TRANSITIONEND, FORCE FIRE TRANSITIONEND     2015-05-09 08:56:51

  Data from iPhone 5 event

Apple finally unveils iPhone 5 on an event at the Moscone Center in San Francisco. At the beginning of the event, Apple showed us some data. There will be 380 Apple Retail Stores opened across 13 countries Last year Apple Retail Store welcomed 83 million customers 7 million Mountain Lion upgrades since last month It ranked the first place in sales for Macbook Air in United States, it has 27% market share in July From April to July, 17 million iPads are sold 84 million iPads are sold until thi...

   Apple,iPhone 5,event,data     2012-09-12 21:26:03

  JavaScript finite state machine

Finite state machine is a very useful design model, it can be used to simulate many events in the world. In short, finite state machine has three features: Number of states is finite At any moment, one object can only be in one state In some condition, it will transfer from one state to another state In JavaScript, finite state machine can be applied in many places. For example, one menu element on a webpage. When the mouse hovers on the menu, the menu will show up, while the mouse moves away...

   JavaScript,Finite state machine,State     2013-09-02 11:00:57

  Why accessing Java HashMap may cause infinite loop in concurrent environment

HashMap in Java is frequently used to handle key/value pairs. But it is not a good candidate to be used in concurrent environment where ConcurrentHashMap should be used instead. If used in concurrent environment, it may cause lots of unexpected behavior even including make the program getting into an infinite loop situation. To understand how this can happen, let's first discuss how HaspMap works internally. In this post we will use implementation of HashMap before Java 8 as example, Java 8 prov...

   JAVA,HASHMAP,INFINITE LOOP     2020-03-29 01:47:00

  Traditional recursion vs Tail recursion

Recursion is a frequently adopted pattern for solving some sort of algorithm problems which need to divide and conquer a big issue and solve the smaller but the same issue first. For example, calculating fibonacci  accumulating sum and calculating factorials. In these kinds of issues, recursion is more straightforward than their loop counterpart. Furthermore, recursion may need less code and looks more concise. For example, let's calculate sum of a set of numbers starting with 0 and st...

   ALGORITHM,RECURSION,TAIL RECURSION,TRADITIONAL RECURSION     2016-09-23 23:54:09

  Sort an array with only one local variable

Array sorting algorithm question is frequently asked during technical interviews. There are lots of sort algorithms including bubble sort, selection sort, insertion sort, quick sort, merge sort etc. Usually interviewees will be asked to implement sort algorithms. But have you ever been asked to sort an array which you are allowed to define ONLY ONE local variable in your algorithm?  Bubble sort can be used to do this actually. Normally a bubble sort algorithm may need three local ...

   JAVASCRIPT,ALGORITHM,SORTING,BUBBLE SORT     2016-10-07 09:46:49

  Tips for improving PHP efficiency

0. Using single quote to replace double quote to enclose string literal, this will be a bit faster. Because PHP engine will search variables in double quoted string. 1. If a method in class can be declared as static, then make it static, this will be 4 times faster. 2. $row["id"] is 7 times faster than $row[id] 3. echo is faster than print, and you should use multiple parameters instead of string concatenation, i.e use comma(,) instead of dot(.) to concatenate string. For example echo $str1,$str...

   PHP, efficiency, tips     2012-10-01 19:39:06

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