1. Session timeout problemThere is a nuance we found with session timing out although the user is still active in the session.  The problem has to do with never modifying the session variable. The GC will clear the session data files based on their last modification time.  Thus if you never modify the session, you simply read from it, then the GC will eventually clean up. To prevent this you need to ensure that your session is modified within the GC delete time.  You can accomplish this like below. if(!isset($_SESSION["last_access"]) || (time() - $_SESSION["last_access"]) >= ...

There are lots of great things about freelance, such as not being tied to a desk, flexible working hours and little, if any, supervision. All freelance web designers probably realize that one of the biggest challenges of their job is the issue of productivity. How to motivate yourself and stay productive every day with no external supervisors telling us to complete a task right now? Here are five practical productivity hacks for all freelance web designers who want to boost their performance.1. Establish a routine (and stick to it)Setting up a clear schedule with slots devoted to specific task...

Internet is improving day by day and the competition is also increasing for every businessman. Having an online presence is a necessity but just online presence won’t work you have to do something extra to grab your potential customers.Websites that are successful online are basically because of three reasons(1) Web technologies are evolving constantly and are allowing for more unique and advanced designs.(2) Technologies have become more accessible than they were earlier, and are empowering more people to use them thoroughly.(3) Awareness among the people about the UX is improving and i...

StackExchange is the most popular and professional IT Q&A site, Under StackExchange, there is StackOverflow and other sub sites. Many of us may wonder how this mega site is maintained and what its performance is. A performance page has been released by StackExchange recently.Below is some statistic about this mega site.560 million page views per month, i.e around 1.9 million PVs per day.For such as big site, it has only 9 web servers and 4 SQL servers(while two of them are in backup mode)185 requests per second, 559 million SQL queries per day with peak rate at 10,700 queries/secTwo redis ...

When developing projects, there are always some common work should be accomplished, for example, encrption/decryption, get IP. As a PHP developer, you should have a list of the handy functions in your toolkit so that you can pick up in every project you work on. Here is a summary of some handy PHP functions.1. PHP encryption/decryptionEncryption/decryption can be used when storing user confidential information such as passwords. Below function uses base64 and MD5 to accomplish encryption/decryption.function encryptDecrypt($key, $string, $decrypt){ if($decrypt){ $decrypted = rtrim(m...

In programming languages such as JavaScript, c/c++, Java and Matlab, you will find that you will get unexpected result when doing float point calculation. For example, when calculating 0.1 + 0.1, you will not get 0.3:> 0.1 + 0.2 == 0.3false> 0.1 + 0.20.30000000000000004Don't be surprised of this result, this is the end result of IEEE 754 standard, float point number cannot be accurately represented according to IEEE 754 because:No enough memory is allocated for representing the numberIt needs a range to ensure the accuracyJavaScript uses 64-bit floating point representation, which is the...

Contact forms are a very common part of any website and anybody can overlook them. Generally people try to choose it as their first solution but they do not realize that they are actually hurting the growth of their business.WordPress currently power more than 66 million websites but it would be good if your website is existing because of one of the most popular Content Management Systems of the world. Everyone starting from blogger to the person sitting next door use this tool for making their website look more amazing.Because of this it looks very easy to browse your plugin directory, findin...

Security is a very important aspect of programming. There are many functions or modules in any kind of real programming language providing security functionalities  In modern websites, we may often get inputs form users all around the world.There is a famous saying which says that never trust user input. So in web programming languages, we will often see functions which will guarantee the security of the data input from users. Today we will cover some of these functions in the most famous open source language  - PHP.In PHP, there are few useful functions which is very handy for preve...