One of the biggest challenges in pursuing a career in software development is to figure out which language you want to work. In addition to commonly used software programming languages like C, C++, Java a lot of new programming languages such as Python, Ruby on Rails have surfaced especially because they are used by a lot of consumer based start-ups these days.

With so many front and back end languages, the choice of learning Java is a failsafe decision and mastering Java can ensure that you have a bright future in software programming.

What is Java

Java is a computer programming language that is designed to be platform independent meaning that the language can virtually run on any hardware platform. This platform independence and an object oriented framework make Java the preferred language of development especially for client-server web applications.

C TRAINING – THE THREE MAIN STAGES OF PROGRAMMING DEVELOPMENT

If you are an aspiring programmer, learning about programming in C is one of the most integral steps of your development.  It is essential that you get the highest quality C training, so that you are well-grounded in the language, and are going to be able to fulfill most of your programming and developmental tasks.  Learning about all aspects of the programming language, including how to fully utilize its portability and design will help you to secure your future in computer programming.  These are some of the concepts you should familiarize yourself with:

·         Major elements of the programming language – This includes things like libraries of functions, using data flow control, and a thourough examination of the basic data types the language is able to address.  As you learn about these fundamental elements, make sure to get practical experience during the course of your C training also, by actually writing programs that follow whatever curriculum you have chosen.

·         Different techniques and other programming elements – Different series of coursework choose to emphasize different things, but try to learn as much as you can about different techniques that are actually employed.  Manipulating both characters and strings, allocating dynamic memory in the proper manner, defining macros, and utilizing the runtime library are all examples of these elements.

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 */

Invoking an external command in Python is a two step process:

from subprocess import call
call(["ls","-1"])