Simple Syntax
Complication results in more bugs in the source code. That's the reason why Java's creators kept the syntax identical to that of C++ because it was easy to understand. On the other hand, they withdrew some perplexing features that were available in C++ but had not so much use. They simply would add to the complexity of the language. For example, the concept of pointers. It's more powerful than C++ despite the fact that many features are eliminated.
Object-Orientation is a technique in which the programmer considers everything as a real-world object. For instance, in a soccer game, the soccer ball is treated as an object that has properties like color, size, etc. and behaviors like moving on the ground, getting hit by the player, etc.
In the same way, referee, players, ground, goal posts are other objects that are part of this game and have their own attributes and functions. All of them interact with each other to provide you an enjoyable gaming experience.
It's such a huge topic that if started to get into the details, will distract us from the main subject. However, you have now an idea about object-orientation. Java is completely an object-oriented language. It turns out that all features of object orientation, become the features of Java.
Those are Inheritance, Polymorphism, Encapsulation, just to name a few.
Object-Oriented
In the real world, things have properties and behaviors. For example, a person's properties include his skin color, weight, etc. On the other hand, eating, walking, etc. are his behaviors.Object-Orientation is a technique in which the programmer considers everything as a real-world object. For instance, in a soccer game, the soccer ball is treated as an object that has properties like color, size, etc. and behaviors like moving on the ground, getting hit by the player, etc.
In the same way, referee, players, ground, goal posts are other objects that are part of this game and have their own attributes and functions. All of them interact with each other to provide you an enjoyable gaming experience.
It's such a huge topic that if started to get into the details, will distract us from the main subject. However, you have now an idea about object-orientation. Java is completely an object-oriented language. It turns out that all features of object orientation, become the features of Java.
Those are Inheritance, Polymorphism, Encapsulation, just to name a few.
Platform-Neutral
"Write once, run anywhere", sometimes called WORA. This famous slogan - used by Java producers - portrays platform-independence. To state it in simpler words, Java programs can be executed on any hardware or software platform that has JVM (Java Virtual Machine) installed on it, irrespective of the platform they're developed on.
But, how is this possible? It takes us to another characteristic of Java. That is, Java is Interpreted. Let's talk about it briefly. In any other high-level language like C, when source code is compiled, it's translated into native machine code that is machine-dependent.
Let's try to understand it with the help of an example.
Suppose you wrote and compiled a program in C on a Windows machine. The output is an executable file that can run only on Windows. If you need to run it on Linux or some other operating system, it has to be recompiled and a separate version for each OS will be released.
Java has a solution for this. When you compile a Java program, instead of machine code, it's converted into bytecode that is machine-independent and is understood by JVM.
The bytecode can run on any machine that has JVM installed in it. What JVM will do is use its component called "Interpreter" to translate the bytecode into the respective machine code.
The flowchart underneath explains the whole process visually.
Furthermore, automatic memory allocation and garbage collection in Java leaves programmers with less to worry about. You need to be clear about one fact that there's no such thing as error-free programming. Errors may still occur while programming in Java, but notably less.
JVM: As we discussed earlier, Java source code is compiled into an intermediate language code called bytecode. JVM verifies it to make sure it has no ability to perform harmful operations on the target computer. It also prevents an exception called "Buffer overflow".
Security Manager implements a security technique, known as Sandboxing. What it does is isolate suspicious programs from the operating system. Those programs are usually provided less control over system resources so that can't be able to perform unwanted tasks.
Security APIs: Developers can use a number of security-related APIs from the class library.
The programs that run on distributed systems are known as distributed programs. Many Java features like Network support, Error handling, platform independence, as a combination, helps in developing efficient distributed applications.
Conditional structures basically make the program dynamic because a particular condition may depend on the user input that the compiler can't predict. It will be evaluated at the runtime.
In Java, it's not limited to conditional statements but much more than that. As you know that Java Virtual Machine interprets the bytecode and loads the required classes at runtime. This feature of Java makes easier the development of evolving applications. How?
If a class is modified, the program will load the updated class because it hasn't been compiled already. In this way, application vendors don't have to worry about distributing, and users don't have to worry about installing the updated versions of applications.
A single processor can't actually handle multiple processes concurrently. What it does is allocate a very short period of time (enough for a processor) to each process and keep switching between processes so faster that gives us the illusion that all process are executing at the same time.
A multithreaded program can be considered as a process that is divided into multiple threads. Each thread occupies a separate core and they run in parallel. In this way, all cores are utilized.
For example, MS Office Word is running on your device. Let's consider it as a process. It may have one thread for grammar checking, one for reading user's keystrokes and so on.
Now you should have an idea about multithreaded programming. It's possible to implement it in other languages but with difficulty. You have to call procedures that are different for different operating systems. But Java comes up with some easy multithreading implementation.
But, how is this possible? It takes us to another characteristic of Java. That is, Java is Interpreted. Let's talk about it briefly. In any other high-level language like C, when source code is compiled, it's translated into native machine code that is machine-dependent.
Let's try to understand it with the help of an example.
Suppose you wrote and compiled a program in C on a Windows machine. The output is an executable file that can run only on Windows. If you need to run it on Linux or some other operating system, it has to be recompiled and a separate version for each OS will be released.
Java has a solution for this. When you compile a Java program, instead of machine code, it's converted into bytecode that is machine-independent and is understood by JVM.
The bytecode can run on any machine that has JVM installed in it. What JVM will do is use its component called "Interpreter" to translate the bytecode into the respective machine code.
The flowchart underneath explains the whole process visually.
Java's Portable
This feature stems from platform-neutrality. Software created in Java can run everywhere. Pick up a Java program, take it anywhere, run it reliably on any device with any operating system as long as one condition is fulfilled. That is, JVM should be available on the target machine.Java's Reliable
Java has taken certain steps to build a reliable programming experience for the users. Its compiler has the ability to catch some runtime errors that would occur in other languages without letting their compilers know. Proper exception handling features are available to prevent abnormal program crashes.Furthermore, automatic memory allocation and garbage collection in Java leaves programmers with less to worry about. You need to be clear about one fact that there's no such thing as error-free programming. Errors may still occur while programming in Java, but notably less.
Security Features
Java has some genius security procedures to offer. Basically, three main elements control security in Java. JVM, Security Manager, and Security APIs.JVM: As we discussed earlier, Java source code is compiled into an intermediate language code called bytecode. JVM verifies it to make sure it has no ability to perform harmful operations on the target computer. It also prevents an exception called "Buffer overflow".
Security Manager implements a security technique, known as Sandboxing. What it does is isolate suspicious programs from the operating system. Those programs are usually provided less control over system resources so that can't be able to perform unwanted tasks.
Security APIs: Developers can use a number of security-related APIs from the class library.
Distributed Programming
A distributed system involves different computer/components located physically in different places but connected together via a network in order to perform a specific task by sending messages to communicate with each other. Multiplayer gaming is the best example of it.The programs that run on distributed systems are known as distributed programs. Many Java features like Network support, Error handling, platform independence, as a combination, helps in developing efficient distributed applications.
Dynamic Development
The word "dynamic", in terms of computer programming, refers to changing program's behavior when it's running. Dynamic programs don't know exactly what the program flow will be when compiled.Conditional structures basically make the program dynamic because a particular condition may depend on the user input that the compiler can't predict. It will be evaluated at the runtime.
In Java, it's not limited to conditional statements but much more than that. As you know that Java Virtual Machine interprets the bytecode and loads the required classes at runtime. This feature of Java makes easier the development of evolving applications. How?
If a class is modified, the program will load the updated class because it hasn't been compiled already. In this way, application vendors don't have to worry about distributing, and users don't have to worry about installing the updated versions of applications.
Multithreaded Programming
These days computers are coming up with multi-core processors, ranging from dual-core to hex core and even more. Each core is managed as a separate processor. They extend the performance and provide faster computing experience. Read on to know how.A single processor can't actually handle multiple processes concurrently. What it does is allocate a very short period of time (enough for a processor) to each process and keep switching between processes so faster that gives us the illusion that all process are executing at the same time.
A multithreaded program can be considered as a process that is divided into multiple threads. Each thread occupies a separate core and they run in parallel. In this way, all cores are utilized.
For example, MS Office Word is running on your device. Let's consider it as a process. It may have one thread for grammar checking, one for reading user's keystrokes and so on.
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| Multithreading explained with example |
