what is java?
Java is a programming language and a platform. Java is a high level,
robust, object-oriented and secure programming language.
Java was developed by Sun Microsystems (which is now the subsidiary of Oracle) in the year 1995. James Gosling is known as
the father of Java. Before Java, its name was Oak. Since Oak was already a registered company, so James Gosling and his
team changed the Oak name to Java.
Java Platforms(Java SE & Java EE)
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There are 4 platforms or editions of Java:
1) Java SE (Java Standard Edition).
It is a Java programming platform. It includes Java programming APIs such as java.lang, java.io, java.net, java.util, java.sql,
java.math etc. It includes core topics like OOPs, String, Regex, Exception, Inner classes, Multithreading, I/O Stream,
Networking, AWT, Swing, Reflection, Collection, etc.
2) Java EE (Java Enterprise Edition)
It is an enterprise platform which is mainly used to develop web and enterprise applications. It is built on the top of the Javabr
SE platform. It includes topics like Servlet, JSP, Web Services, EJB, JPA, etc.
Java Platforms(Java ME & Java FX)
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There are 4 platforms or editions of Java:
3) Java ME (Java Micro Edition)
It is a micro platform which is mainly used to develop mobile applications.
4) Java FX
It is used to develop rich internet applications. It uses a light-weight user interface API.
Audience:Â
 Our Java programming tutorial is designed to help beginners and professionals.
Java Platforms(Java SE & Java EE)
Â
There are 4 platforms or editions of Java:
1) Java SE (Java Standard Edition).
It is a Java programming platform. It includes Java programming APIs such as java.lang, java.io, java.net, java.util, java.sql,
java.math etc. It includes core topics like OOPs, String, Regex, Exception, Inner classes, Multithreading, I/O Stream,
Networking, AWT, Swing, Reflection, Collection, etc.
2) Java EE (Java Enterprise Edition)
It is an enterprise platform which is mainly used to develop web and enterprise applications. It is built on the top of the Javabr
SE platform. It includes topics like Servlet, JSP, Web Services, EJB, JPA, etc.
public class MainPerson {
public static void main(String[] args) {
int age;// scaler variable declaration //scaler variable - can hold only one value
age = 5;// initializing age variable with value 5
System.out.println("age is " + age);
age = 10;// assigning value 10 in variable age
System.out.println("now age is " + age);
Person karim; // object variable declaration
// here we are declaring an object variable named Karim
// karim's Data Type Person
// here karim is an object variable
karim = new Person(); // instantiating karim with default values
// by using Person() method
System.out.println("id = " + karim.id);
karim.id = 1;
System.out.println("now id = " + karim.id);
System.out.println("name = " + karim.name);
karim.name = "Karim Ali";
System.out.println("now name = " + karim.name);
// now create Maria
Person maria;
maria = new Person();
maria.id = 2;
System.out.println("Maria id is " + maria.id);
}
}
