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  How big are PHP arrays (and values) really? (Hint: BIG!)

Upfront I want to thank Johannes and Tyrael for their help in finding some of the more hidden memory usage. In this post I want to investigate the memory usage of PHP arrays (and values in general) using the following script as an example, which creates 100000 unique integer array elements and measures the resulting memory usage: <?php $startMemory = memory_get_usage(); $array = range(1, 100000); echo memory_get_usage() - $startMemory, ' bytes'; How much would you expect it to ...

   PHP,Array,Memory occupation,Garbage collection     2011-12-16 10:06:04

  Java vs F#

Dr Cliff Click of Azul Systems, specialists in manycore JVM systems, recently published a blog post about the performance of Java compared primarily to C and C++ but also discussing C# and .NET. Three of Cliff's comments are of particular interest:Under the heading "Places where C/C++ beats Java for obvious reasons":"Value Types, such as a 'Complex' type require a full object in Java." - Dr Cliff ClickWhat Cliff forgot to mention is that .NET also provides value types and a far more compell...

   Java,F#,Performance,JVM     2012-03-07 05:07:31

  How Java Application Developers Can Build Secure Internet Based Apps?

There are few compiled solution tested by experts to guide Java application development and maintenance team how they can start safe journey on Internet. Strong encryption, wise passwords, secure hardware are few of the tech tools that should be used by Java app development team to secure their Internet based apps.   The Internet is most amazing yet most risky platform where nobody knows either they are doing safe transaction on Internet or there is some dog watching out for data packets t...

   JAVA APPLICATION MAINTENANCE,JAVA APPLICATION DEVELOPMENT     2015-09-16 02:13:17

  Is Java Set ordered or not?

“Is Java Set ordered or not? ” is the most popular question asked when you interview for a Java Developer position. Many fail to answer it, and I have to admit I was one of the many. I have known the answer is “Yes and No” for a long time. No. HashSet is not ordered. Yes.TreeSet is ordered. If the interviewer continues with some follow up questions, I’m not confident that I know the answer then. Why is TreeSet ordered? Are there any other ordered S...

   ORDER,SORTEDSET,HASHSET,JAVA     2021-02-11 06:55:00

  What I learned interviewing with Google

Over the last few weeks I’ve been interviewing with Google for a job doing primarily JavaScript development. I didn’t end up getting the job but I thought I would share the process of interviewing for Google as it was both very exciting and a humbling experience. I can’t reveal everything as I’m under a few NDAs. I’m not going to mention the products or teams that I was interviewing for but you may be able to guess. For those that don’t know me, I...

   Google,Experience,Interview,Algorithm     2012-02-10 06:19:17

  JSON in JavaScript

When sending an AJAX request to the server, the response can have two formats : XMLHttpRequest.responseXML to access data with XML format and XMLHttpRequest.responseText to access data with string format. XML is the standard data transfer format, but one weakness is it's troublesome to parse and retrieve the data. JSON(JavaScript Object Notation) is a light weight data interchange format, we call it the JavaScript object representation. The advantage of using JSON as the data format is itself is...

   JSON,JavaScript     2013-05-04 23:25:57

  How does MySQL handle DROP TABLE

A few days ago, when executing DROP TABLE in MySQL, all processes including DDL and DML were hung until DROP TABLE was completed. I am confused about this phenomenon. I have reviewed the source codes of MySQL to check how MySQL internally handle DROP TABLE. When user trigger DROP TABLE command: ########################MySQL SERVER drop table######################## /* Sql_table.cc  delete (drop) tables. */bool mysql_rm_table( )   /*   Execute the drop of a normal or temporary...

   MySQL,DROP TABLE     2012-09-24 11:34:05

  How GitHub Works: Be Asynchronous

This is — by far — my favorite aspect of working at GitHub. Everything is asynchronous. Chat GitHub didn’t have an office for the first two years. Chat rooms (in our case, Campfire) is where things got done. Today we’ve moved into our second office, and Campfire is still where we get things done. There’s a reason for that: chat is asynchronous. Asynchronous communication means I can take a step out for lunch and catch up on transcripts when I get back. Async...

   GitHub,Work,Style,Asynchronous,Efficienc     2011-08-19 07:44:20

  Why exception would be thrown when deleting element while looping through HashMap in Java

HashMap and other Collection types are frequently used in Java application programming. This post will explain why exception would be thrown when deleting element with Map.remove() while looping through a Map using Iterator. This issue would also occur to other Collection types such as Set, List. Below is a sample code snippet demonstrating the exception thrown. Map<String,String> map = Collections.synchronizedMap(new TreeMap<String,String>()); map.put("key1","value1"); map.put("ke...

   JAVA,HASHMAP,CONCURRENTMODIFICATIONEXCEPTION     2018-06-30 12:49:09

  Essential skills any web developer should have

As a web developer, besides writing HTML code, there is much more to do before the site can go live. You may consider about user experience, device compatibility, security etc. To be a good web developer, you should acquire some essential skills for web development. Below we list some of them. Some of them you may be familiar with a long time ago, but definitely some of them you may not be so familiar with or even never hear about before. Interface and User Experience Be aware that browsers imp...

   Web development,User experience     2014-03-21 06:44:49

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