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There is no equivalent mechanism in Java. Thus there are also no const methods. Const-correctness cannot be enforced in Java, although by use of interfaces and defining a read-only interface to the class and passing this around, one can ensure that objects can be passed around the system in a way that they cannot be modified.
However, Java initially left open the possibility of implementing const, noticeable in that const is a reserved word, though it is not actually used as a keyword. Instead, Java has the object-oriented keyword final , which is used to qualify attributes (and thence also for local variables) as constant, but not to qualify types.
In C#, only C# built-in types can be declared as const; user-defined types, including classes, structs, and arrays, cannot be const. [22] Java does not have const – it instead has final, which can be applied to local "variable" declarations and applies to the identifier, not the type. It has a different object-oriented use for object members ...
Unless a developer checks any implemented interfaces when adding a constant to a class, or does so but makes a typo in the name of the added constant, the value of a constant can be silently changed. Consider Example 2 below. Note that the Java libraries use constant interface pattern themselves.
The Java standard library provides utility classes to use with enumerations. The EnumSet class implements a Set of enum values; it is implemented as a bit array, which makes it very compact and as efficient as explicit bit manipulation, but safer. The EnumMap class implements a Map of enum values to object. It is implemented as an array, with ...
An exception is when a processor is designed to use a particular bytecode directly as its machine code, such as is the case with Java processors. Machine code and assembly code are sometimes called native code when referring to platform-dependent parts of language features or libraries.
Class-based object-oriented programming languages support objects defined by their class. Class definitions include member data. Message passing is a key concept, if not the main concept, in object-oriented languages. Polymorphic functions parameterized by the class of some of their arguments are typically called methods.
Many files have such constants that identify the contained data. Detecting such constants in files is a simple and effective way of distinguishing between many file formats and can yield further run-time information. Examples. Compiled Java class files and Mach-O binaries start with hex CAFEBABE.