History of Java
The java programming language is becoming more and more popular each day. It is the language without which one cannot even hope to a land a job these days. But has somebody even wondered how this language came about? There are many stories about, many books have been written. Here is my version (not approved by Sun Microsystems).
The java programming language originated in Indonesia. It was meant to be used by the tourists that visit that country each year. Why would tourists want to use computer? Well, these are no ordinary tourists. They are rich tourists. Have they not been rich, they would not travel half way around the world to visit this place. Most people would be content to see just what is available near by. For example, if you are a texan living in Dallas, you will visit the stockyards or may be the trinity river park. If you live in New Orleans area, you would see st. mary's bayou. Once in your lifetime, one will probably visit Hawaii or Niagara.
But going to Indonesia and its islands, Bali, Java, etc is not for the ordinary people. Anyway, coming back to the question why these tourists need to use computer programs. They go there not just to have fun and also get some work done in a fun atmosphere as these people are very important people.
From the very start java was supposed to be computer independent. That means if you write a program in java in one computer, it should run in all computers. This was necessary because tourists bring all kinds of computers with them. Some bring Windows machine, some Apple mackintosh. Some of the affluent ones bring Sun server workstations or even a super computer.
Before starting to create java they also sought to see if there have similar stuff done already. Even though they could find none, they found they can use lots of feature from some existing laguages.
One such language they found was C++. C++ was an advancement over the language called C. In fact, ideas of C++ was already hidden in C. In that language, one can increment a variable, say i, by applying the ++ operator e.g. i++. This would increase the value of the variable i by one. If i had a value of 5, it would make it 6, etc. What a vision!
Anyway, coming back to C++, it made an important advancement over C by introducing the idea of a class. To understand class, one has to undestand structure which was already used in C. The structure is a group of variables. For example, you have a name, an address, age etc. for any person.
In stead of using them separately, in C one can group them together and call it a person. The creator of C++ said there is no need to expose these variables (name, address, etc) to the outside world. They said these details should be hidden from the outside world. They called this concept encapsulation.
Another important contribution of C++ was the concept of inheritence. This concept can be best explained by example. Let's go back to the example of the person. A person is very general concept. There can be many different kinds of persons, e.g doctors, lawyers, teachers, or just a bum! But each of these people have a name, an address, age etc.
Even a bum has all these. The creator of C++ thought one can define a base class call person and other classes can be derived from it. In plain english, this would mean, a doctor is special kind of person, lawyer is another special kind of person. Now the common attributes of all these kinds of people can be put in the person class and special attributes can be put in the derived classes, e.g. hospital for the doctor, court for the lawyer, and nothing for the bum.
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