The python keyword global is used in a function to distinguish a local representation of a variable with the same name. 

glbvar = 0

def setglbvar():
    global glbvar # include this declaration so that updates to glbvar are NOT LOCAL to this function
    glbvar = 1

def printglbvar():
    print glbvar     # No need for global declaration to read value of globvar

setglbvar()
printglbvar()       # Prints 1

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 */

I suspect that many of you are familiar with the term "hard coding a value" whereby the age of an individual or their location is written into the condition (or action) of a business rule (in this case) as shown below:

if customer.age > 21 and customer.city == 'denver'

then ...

Such coding practices are perfectly expectable provided that the conditional values, age and city, never change. They become entirely unacceptable if a need for different values could be anticipated. A classic example of where this practice occurred that caused considerable heartache in the IT industry was the Y2K issue where dates were updated using only the last 2 digits of a four digit number because the first 2 digits were hard-coded to 19 i.e. 1998, 1999. All was well provided that the date did not advance to a time beyond the 1900’s since no one could be certain of what would happen when the millennia arrived (2000). A considerably amount of work (albeit boring) and money, approximately $200 billion, went into revising systems by way of software rewrites and computer chip replacements in order to thwart any detrimental outcomes. It is obvious how a simple change or an assumption can have sweeping consequences.

You may wonder what Y2K has to do with Business Rule Management Systems (BRMS). Well, what if we considered rules themselves to be hard-coded. If we were to write 100s of rules in Java, .NET or whatever language that only worked for a given scenario or assumption, would that not constitute hard-coded logic? By hard-coded, we obviously mean compiled. For example, if a credit card company has a variety of bonus campaigns, each with their own unique list of rules that may change within a week’s time, what would be the most effective way of writing software to deal with these responsibilities?

Many individuals are looking to break into a video game designing career, and it's no surprise. A $9 billion industry, the video game designing business has appeal to gamers and non-gamers alike. High salaries and high rates of job satisfaction are typical in the field.

In order to design video games, however, you need a certain skill set. Computer programming is first on the list. While games are made using almost all languages, the most popular programming language for video games is C++, because of its object-oriented nature and because it compiles to binary. The next most popular languages for games are C and Java, but others such as C# and assembly language are also used. A strong background in math is usually required to learn these languages. Individuals wishing to design games should also have an extensive knowledge of both PCs and Macs.

There are many colleges and universities that offer classes not only in programming but also classes specifically on game design. Some of these schools have alliances with game developing companies, leading to jobs for students upon graduation. Programming video games can be lucrative. The average game designer's salary is $62,500, with $55,000 at the low end and $85,000 at the high end.

Programmers are not the only individuals needed to make a video game, however. There are multiple career paths within the gaming industry, including specialists in audio, design, production, visual arts and business.

Designing a video game can be an long, expensive process. The average budget for a modern multiplatform video game is $18-$28 million, with some high-profile games costing as much as $40 million. Making the game, from conception to sale, can take several months to several years. Some games have taken a notoriously long time to make; for example, 3D Realms' Duke Nukem Forever was announced in April 1997 and did not make it to shelves until July 2011.

Video game programmers have a high level of job satisfaction. In a March 2013 survey conducted by Game Developer magazine, 29 percent of game programmers were very satisfied with their jobs, and 39 percent were somewhat satisfied.

If you're interested in a game development career, now's the time to get moving. Take advantage of the many online resources available regarding these careers and start learning right away.