@see Associated class name Class, method, or variable (Web hosting provider)
@see Associated class name Class, method, or variable @author Author name Class @version Version string Class @param Parameter name and description Method @return Description of return value Method @exception Exception name and description Method @deprecated Declares an item to be obsolete Class, method, or variable 4.3 Types The type system of a programming language describes how its data elements (variables and constants) are associated with actual storage. In a statically typed language, like C or C++, the type of a data element is a simple, unchanging attribute that often corresponds directly to some underlying hardware phenomenon, like a register value or a pointer indirection. In a more dynamic language like Smalltalk or Lisp, variables can be assigned arbitrary elements and can effectively change their type throughout their lifetime. A considerable amount of overhead goes into validating what happens in these languages at runtime. Scripting languages like Perl and Tcl achieve ease of use by providing drastically simplified type systems in which only certain data elements can be stored in variables, and values are unified into a common representation, such as strings. Java combines the best features of both statically and dynamically typed languages. As in a statically typed language, every variable and programming element in Java has a type that is known at compile time, so the runtime system doesn’t normally have to check the type validity of assignments while the code is executing. Unlike C or C++, though, Java also maintains runtime information about objects and uses this to allow truly safe runtime polymorphism and casting (using an object as a type other than its declared type). Java data types fall into two categories. Primitive types represent simple values that have built-in functionality in the language; they are fixed elements, such as literal constants and numbers. Reference types (or class types) include objects and arrays; they are called reference types because they are passed “by reference,” as we’ll explain shortly. 4.3.1 Primitive Types Numbers, characters, and boolean values are fundamental elements in Java. Unlike some other (perhaps more pure) object-oriented languages, they are not objects. For those situations where it’s desirable to treat a primitive value as an object, Java provides “wrapper” classes (see Chapter 9). One major advantage of treating primitive values as such is that the Java compiler can more readily optimize their usage. Another important portability feature of Java is that primitive types are precisely defined. For example, you never have to worry about the size of an int on a particular platform; it’s always a 32-bit, signed, two’s complement number. Table 4.2 summarizes Java’s primitive types. Table 4.2. Java Primitive Data Types Type Definition Boolean true or false Char 16-bit Unicode character Byte 8-bit signed two’s complement integer
Note: If you are looking for reliable webhost to maintain and run your java application check Vision java hosting services