Skip to main content

Introduction to Java

Java is a programming language developed by James Gosling from Sun Microsystems in 1991. Their intention was, to write a program once and then run this program on multiple operating systems. The first version of Java (Java 1.0) was released in 1995. Sun Microsystems was acquired by the Oracle Corporation in 2010.

Please do not confuse with java's versioning analogy, Java 1.8 is also known as Java 8.

Platform independent: Java programs use the Java virtual machine as abstraction and do not access the operating system directly. This makes Java programs highly portable. A Java program (which is standard-compliant and follows certain rules) can run unmodified on all supported platforms, e.g., Windows or Linux.

Basic features:
  • Object-orientated programming language: Except the primitive data types(int, float, char, boolean), all elements in Java are objects.
  • Strongly-typed programming language: Java is strongly-typed, e.g., the types of the used variables must be pre-defined and conversion to other objects is relatively strict, e.g., must be done in most cases by the programmer.
  • Interpreted and compiled language: Java source code is compiled into the bytecode format which does not depend on the target platform. These bytecode instructions will be interpreted by the Java Virtual machine (JVM).
  • Automatic memory management: Java manages the memory allocation and de-allocation for creating new objects. The program does not have direct access to the memory. The so-called garbage collector automatically deletes objects to which no active pointer exists.
The Java syntax is similar to C++. 
Java is case-sensitive, e.g., variables myValue and myvalue are treated as different variables.

Comments

  1. For example, our lucky participant Jessica who received two huge Jackpots in two years. Our most popular Jackpot slots embody Mega Fortune, Hall of Gods, Mega Moolah, Joker 메리트카지노 Millions, and Siberian Storm. Mr Green's app, which is available for Android and iOS, additionally be|can be} an option when you prefer to play on your smartphone. The app options intuitive and easy-to-use navigation with tons of options that will ensure you could have} an outstanding gaming expertise. With the app, have the ability to|you presumably can} wager on your favorite slots, stay casino tables, Keno, and sports activities occasions (live and pre-event).

    ReplyDelete

Post a Comment

suggestions

Popular posts from this blog

Why "F" and "L" suffix | (10.0F, 10L)

Let us take it this way, We will create their needs. So we will get why they are needed. Try to guess, which functions will be executed in the following program: public class MyClass {     public static void main(String args[]) {         MyClass obj = new MyClass();         obj.fun1(10);     }     void fun1(byte val){         System.out.println(val);     }     void fun1(int val){         System.out.println(val);     }     void fun1(float val){         System.out.println(val);     }     void fun1(long val){         System.out.println(val);     }     } It seems like every method is capable to run this program because 10 is still literal because It has no data type. Before Java, In previous technologies, this scenario gave an ambiguity error. But Java solves this problem by removing the concepts of literals. It means Java provide a data type immediately when these born. So here 10 is no more literal. Java provides Integer data type for it. So now it is of Integer t

only large files upload on S3 | Ruby On Rails

models/attachment.rb class Attachment < ApplicationRecord after_initialize :set_storage private def set_storage # larger that 5mb file would be upload on s3 if file . blob . byte_size > 5_000_000 Rails . application . config . active_storage . service = :amazon else Rails . application . config . active_storage . service = :local end end # end of private end

Typecasting | How is Long to Float Conversion possible?

We will take a brief description of Typecasting and will try to do focus on Log to Float Conversion. Typecasting: Assigning a value of one data type to another. When we assign a value of smaller data type to a bigger one. it is called Widening. Java did this conversion automatically as they are compatible. As shown in the following figure: One another kind of conversion, when automatic conversion not possible i.e. when they are not compatible is Shortening. It will be just opposite of above and diagram will be reversed. How is Long to Float Conversion possible? If we look carefully at the diagram, there is one conversion which looks questionable is Long(8 bytes) to Float(4 bytes) conversion. It looks like data lossy conversion. Actually, Type conversion does two things: Either change in range or change in behavior or both. Change in Range: short a = 3456 // this value can be varied within the range of -32768 to 32767 int b = a // now this value can be varied wi