I will begin our blog on Java Tutorial with an incredibly important aspect of java development:  memory management.  The importance of this topic should not be minimized as an application's performance and footprint size are at stake.

From the outset, the Java Virtual Machine (JVM) manages memory via a mechanism known as Garbage Collection (GC).  The Garbage collector

• Manages the heap memory.   All obects are stored on the heap; therefore, all objects are managed.  The keyword, new, allocates the requisite memory to instantiate an object and places the newly allocated memory on the heap.  This object is marked as live until it is no longer being reference.
• Deallocates or reclaims those objects that are no longer being referened. 
• Traditionally, employs a Mark and Sweep algorithm.  In the mark phase, the collector identifies which objects are still alive.  The sweep phase identifies objects that are no longer alive.
• Deallocates the memory of objects that are not marked as live.
• Is automatically run by the JVM and not explicitely called by the Java developer.  Unlike languages such as C++, the Java developer has no explict control over memory management.
• Does not manage the stack.  Local primitive types and local object references are not managed by the GC.

So if the Java developer has no control over memory management, why even worry about the GC?  It turns out that memory management is an integral part of an application's performance, all things being equal.  The more memory that is required for the application to run, the greater the likelihood that computational efficiency suffers. To that end, the developer has to take into account the amount of memory being allocated when writing code.  This translates into the amount of heap memory being consumed.

Memory is split into two types:  stack and heap.  Stack memory is memory set aside for a thread of execution e.g. a function.  When a function is called, a block of memory is reserved for those variables local to the function, provided that they are either a type of Java primitive or an object reference.  Upon runtime completion of the function call, the reserved memory block is now available for the next thread of execution.  Heap memory, on the otherhand, is dynamically allocated.  That is, there is no set pattern for allocating or deallocating this memory.  Therefore, keeping track or managing this type of memory is a complicated process. In Java, such memory is allocated when instantiating an object:

String s = new String();  // new operator being employed
String m = "A String";    /* object instantiated by the JVM and then being set to a value.  The JVM
calls the new operator */

Planning on a little spring cleaning and getting rid of all those old electronics? With the way technology changes so quickly, it seems like we no sooner have one new electronic piece and there’s a new one on the market that we absolutely have to have. The result is a ton of used electronics stored away. Now it’s time to get rid of everything, here are some tips on what to do with all that old tech stuff and how to do it safely.

Save on Landfill Waste

Few people really realize where their electronics wind up when they throw them in the trash or dumpster. They assume they’re getting taken care of and just forget about them. According to the Environmental Protection Agency, one of the fastest growing components of landfill waste is electronics. The unfortunate part of this is that these electronics are filled with lead, mercury and other toxic chemicals – chemicals that find their way into our soil and water.

This results in the contamination of our lakes, streams and soil. The best way to avoid this is by knowing where your electronics are going and to dispose of them safely. Contact the recycling center in your area and ask for the best place to dispose of your old electronics.

Think of Security

Our lives are filled with electronic technology, whether it’s in the form of computers, tablets, smart phones or video games. Most of these electronics allow network sharing with people all over the world. With identity theft such a growing concern, much of our private lives and personal information is entered in the hard drives of these items.

Before you dispose of any electronics, make sure the hard drives are wiped clean of all personal information. This requires more than just “deleting” files. If you’re not sure how to correctly get rid of the information, contact a professional to do this for you. Even if you have to pay to have it done, it’s a minimal expense compared to having your private information stolen.

Find New Homes for Your Electronics

Once you’ve cleaned out your electronics of personal information, they may still be worth something to other individuals. You may know of a child or elderly person who would really appreciate a “new” computer or a tablet. Someone who has never owned a smart phone or laptop may be thrilled to suddenly own one, even if they are obsolete to you.

If you can’t find anyone that wants them, consider selling them on places like eBay, Craigslist or one of the many other online auction sites. The old saying, “one man’s junk is another man’s gold” is especially true when it comes to electronics. Many people like building computers using their own parts.

Students in computer-related programs also utilize used electronics as a form of hands-on training. Most schools also take in donated computers, televisions and cell phones. Contact your electric company or school district to get information on where you can take your old electronics. You’ll be not only cleaning out your house but also helping the environment.

Related:

Cloud Computing: What It Means and How It Could Threaten the Traditional Outsourcing Model

The importance of variables in any programming language can’t be emphasised enough. Even if you are a novice, the chances are good that you will have been using variables for quite a while now.

They are the cornerstone of any language and without them we would not be able to accomplish much of anything. However, most of you up until this point have probably only been working with standard variables, variables which can hold single values such as an integer, a single character, or a string of text.

In this tutorial we are going to take a look at a more special type of variable called an array. Arrays can seem quite daunting at first glance but once you get used to working with them you will wonder how you ever managed to program without them.

The reason arrays are special is because they can hold more than one value. Think about this: say you create a variable which contains a line of text like the code below:

No matter what type of business you’re in, boosting your bottom line is always in the back of your mind. In a rough economy, it can be tempting to focus too much on pulling in more money and not enough on containing it from within.

That’s right, containing it. You have the potential to lose hundreds of thousands of dollars every year right under your nose from something as simple as lack of or ineffective computer training.

How much do the employees you have working for you right now really understand about technology? How good is your IT tech department? Technology changes faster than a blink of an eye and oftentimes, businesses struggle to keep their top employees trained.

With millions of dollars being lost to Internet espionage, file corruption and other computer crimes, staying on top of changes is essential. Recently, online learning centers have been emerging as the go-to method for quick and inexpensive learning. Unfortunately, this type of computer learning isn’t always the best solution.