Java: Introduction to Operators, understanding Assignment and Arithmetic Operators

Do check out the video! We start with the introduction to operators and the precedence of operators, then we have a look at the simple assignment operators and then we move on to the Arithmetic operators and discuss the Modulo operator in detail.

Java: Introduction to Operators, understanding Assignment and Arithmetic Operators

Autoboxing and Unboxing in Java

The Autoboxing and Unboxing  was released with the Java 5.

Autoboxing

During assignment, the automatic transformation of primitive  type(int, float, double etc.) into their object equivalents or wrapper type(Integer, Float, Double,etc) is known as Autoboxing.

During assignment or calling of constructor, the automatic transformation of wrapper types into their primitive equivalent  is known as Unboxing. Here is a quick video that will explain you the same.

For details visit: http://www.roseindia.net/javatutorials/autoboxing_yourself_in_JDK_1_5.shtml

Conversion of int into Integer

int inactive = 0;
inactive = new Integer(5); //auto - unboxing
Integer intObject = 5; //autoboxing

Java: Introduction to Strings

A string is an ordered sequence of symbols. Sting class is included in java.lang package. So each class in Java, can use String class without importing any package. The String class represents character strings. All string literals in Java programs, such as "abc", are implemented as instances of this class. 

Documentation:

http://download.oracle.com/javase/1.4.2/docs/api/java/lang/String.html

Comparing Strings:

http://www.cs.geneseo.edu/~baldwin/reference/java-strings.html

Exception handling in Java

An exception is an event, which occurs during the execution of a program, that disrupts the normal flow of the program's instructions. When an error occurs within a method, the method creates an object and hands it off to the runtime system. The object, called an exception object, contains information about the error, including its type and the state of the program when the error occurred. Creating an exception object and handing it to the runtime system is called throwing an exception. 

Text Source: http://docs.oracle.com/javase/tutorial/essential/exceptions/