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Java Keywords
In the Java programming language, a keyword is any one of 68 reserved words that have a predefined meaning in the language. Because of this, programmers cannot use keywords in some contexts, such as names for variables, methods, classes, or as any other identifier. Of these 68 keywords, 17 of them are only contextually reserved, and can sometimes be used as an identifier, unlike standard reserved words. Due to their special functions in the language, most integrated development environments for Java use syntax highlighting to display keywords in a different colour for easy identification. Keywords The following words are keywords and cannot be used as identifiers under any circumstances. ;_ :Added in Java 9, the underscore has become a keyword and cannot be used as a variable name anymore. ; abstract : A method with no definition must be declared as abstract and the class containing it must be declared as abstract. Abstract classes cannot be instantiated. Abstract methods must ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Keywords Highlighted
Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, projected to rise to 158 million at mid 2025, Java is the world's most populous island, home to approximately 55.7% of the Indonesian population (only approximately 44.3% of Indonesian population live outside Java). Indonesia's capital city, Jakarta, is on Java's northwestern coast. Many of the best known events in Indonesian history took place on Java. It was the centre of powerful Hindu-Buddhist empires, the Islamic sultanates, and the core of the colonial Dutch East Indies. Java was also the center of the Indonesian struggle for independence during the 1930s and 1940s. Java dominates Indonesia politically, economically and culturally. Four of Indonesia's eight UNESCO world heritage sites are located in Java: Ujung Kulon National Par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Switch Statement
In computer programming languages, a switch statement is a type of selection control mechanism used to allow the value of a variable or expression to change the control flow of program execution via search and map. Switch statements function somewhat similarly to the if statement used in programming languages like C/ C++, C#, Visual Basic .NET, Java and exist in most high-level imperative programming languages such as Pascal, Ada, C/ C++, C#, Visual Basic .NET, Java, and in many other types of language, using such keywords as switch, case, select, or inspect. Switch statements come in two main variants: a structured switch, as in Pascal, which takes exactly one branch, and an unstructured switch, as in C, which functions as a type of goto. The main reasons for using a switch include improving clarity, by reducing otherwise repetitive coding, and (if the heuristics permit) also offering the potential for faster execution through easier compiler optimization in many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
While
''While'' is a word in the English language that functions both as a noun and as a subordinating conjunction. Its meaning varies largely based on its intended function, position in the phrase and even the writer or speaker's regional dialect. As a conjunction, it is synonymous with the word ''whilst'', a form often considered archaic in American English, as well as in some style guides on both sides of the Atlantic. Usage Noun ''A while'' and ''awhile'' are often confused due to the fact that ''while'' is often accompanied by the indefinite article. The main difference is that ''a while'' means "an amount of time" or "some duration" whereas ''awhile'' is an adverb meaning "''for'' some amount of time" or "''for'' some duration". :"I slept for a while before dinner." :"I slept awhile before dinner." Both of these sentences yield the same effective meaning. ''Whilst'' is only a conjunction, and so its use here would be incorrect. Conjunction The primary function of the word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Do While Loop
In many computer programming Programming language, languages, a do while loop is a control flow Statement (computer science), statement that executes a block of code and then either repeats the block or exits the loop depending on a given Boolean data type, boolean condition. The ''do while'' construct consists of a process symbol and a condition. First the code within the block is executed. Then the condition is evaluated. If the condition is Truth, true the code within the block is executed again. This repeats until the condition becomes False (logic), false. Do while loops check the condition after the block of code is executed. This control structure can be known as a post-test loop. This means the do-while loop is an exit-condition loop. However a while loop will test the condition before the code within the block is executed. This means that the code is always executed first and then the expression or test condition is evaluated. This process is repeated as long as the ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Annotation
In the Java computer programming language, an annotation is a form of syntactic metadata that can be added to Java source code. Class (computer programming), Classes, Method (computer programming), methods, Variable (computer science), variables, Parameter (computer programming), parameters and Java packages may be annotated. Like Javadoc tags, Java annotations can be read from source files. Unlike Javadoc tags, Java annotations can also be embedded in and read from Java class files generated by the Java compiler. This allows annotations to be retained by the Java virtual machine at Run time (program lifecycle phase), run-time and read via reflection (computer science), reflection. It is possible to create meta-annotations out of the existing ones in Java. History The Java (software platform), Java platform has various ''ad-hoc'' annotation mechanisms—for example, the ''transient'' modifier, or the ''@Deprecated'' javadoc tag. The Java Specification Request JSR-175 introduc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continue (Java)
In computer science, control flow (or flow of control) is the order in which individual statements, instructions or function calls of an imperative program are executed or evaluated. The emphasis on explicit control flow distinguishes an ''imperative programming'' language from a ''declarative programming'' language. Within an imperative programming language, a ''control flow statement'' is a statement that results in a choice being made as to which of two or more paths to follow. For non-strict functional languages, functions and language constructs exist to achieve the same result, but they are usually not termed control flow statements. A set of statements is in turn generally structured as a block, which in addition to grouping, also defines a lexical scope. Interrupts and signals are low-level mechanisms that can alter the flow of control in a way similar to a subroutine, but usually occur as a response to some external stimulus or event (that can occur asynchronously) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superclass (computer Science)
In object-oriented programming, inheritance is the mechanism of basing an object or class upon another object ( prototype-based inheritance) or class ( class-based inheritance), retaining similar implementation. Also defined as deriving new classes ( sub classes) from existing ones such as super class or base class and then forming them into a hierarchy of classes. In most class-based object-oriented languages like C++, an object created through inheritance, a "child object", acquires all the properties and behaviors of the "parent object", with the exception of: constructors, destructors, overloaded operators and friend functions of the base class. Inheritance allows programmers to create classes that are built upon existing classes, to specify a new implementation while maintaining the same behaviors ( realizing an interface), to reuse code and to independently extend original software via public classes and interfaces. The relationships of objects or classes through inher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interface (computer Science)
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any variation of a physical quantity. The protocol defines the rules, syntax, semantics, and synchronization of communication and possible error recovery methods. Protocols may be implemented by hardware, software, or a combination of both. Communicating systems use well-defined formats for exchanging various messages. Each message has an exact meaning intended to elicit a response from a range of possible responses predetermined for that particular situation. The specified behavior is typically independent of how it is to be implemented. Communication protocols have to be agreed upon by the parties involved. To reach an agreement, a protocol may be developed into a technical standard. A programming language describes the same for computations, so there is a close analogy between protocols and programming languages: ''protocols are to communica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inner Class
In object-oriented programming (OOP), an inner class or nested class is a class declared entirely within the body of another class or interface. It is distinguished from a subclass. Overview An instance of a normal or top-level class can exist on its own. By contrast, an instance of an inner class cannot be instantiated without being bound to a top-level class. Let us take the abstract notion of a Car with four Wheels. Our Wheels have a specific feature that relies on being part of our Car. This notion does not represent the Wheels as Wheels in a more general form that could be part of any vehicle. Instead, it represents them as specific to a Car. We can model this notion using inner classes as follows: We have the top-level class Car. Instances of class Car are composed of four instances of the class Wheel. This particular implementation of Wheel is specific to a car, so the code does not model the general notion of a wheel that would be better represented as a top-level class. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field (computer Science)
In data hierarchy, a field (data field) is a Variable (computer science), variable in a record (computer science), record. A record, also known as a data structure, allows logically related data to be identified by a single name. Identifying related data as a single group is central to the construction of understandable computer programs. The individual fields in a record may be accessed by name, just like any variable in a computer program. Each field in a record has two components. One component is the field's data type, datatype Declaration (computer programming), declaration. The other component is the field's identifier. Memory fields Fields may be stored in random access memory (RAM). The following Pascal (programming language), Pascal record definition has three field identifiers: firstName, lastName, and age. The two name fields have a datatype of an Array (data structure), array of Character (computing), character. The age field has a datatype of integer. type PersonRec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object (computer Science)
In software development, an object is an entity that has state, behavior, and identity. An object can model some part of reality or can be an invention of the design process whose collaborations with other such objects serve as the mechanisms that provide some higher-level behavior. Put another way, an object represents an individual, identifiable item, unit, or entity, either real or abstract, with a well-defined role in the problem domain. A programming language can be classified based on its support for objects. A language that provides an encapsulation construct for state, behavior, and identity is classified as object-based. If the language also provides polymorphism and inheritance it is classified as object-oriented. A language that supports creating an object from a class is classified as class-based. A language that supports object creation via a template object is classified as prototype-based. The concept of object is used in many different software contexts, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Character (computing)
In computing and telecommunications, a character is the internal representation of a character (symbol) used within a computer or system. Examples of characters include letters, numerical digits, punctuation marks (such as "." or "-"), and whitespace. The concept also includes control characters, which do not correspond to visible symbols but rather to instructions to format or process the text. Examples of control characters include carriage return and tab as well as other instructions to printers or other devices that display or otherwise process text. Characters are typically combined into '' strings''. Historically, the term ''character'' was used to denote a specific number of contiguous bits. While a character is most commonly assumed to refer to 8 bits (one byte) today, other options like the 6-bit character code were once popular, and the 5-bit Baudot code has been used in the past as well. The term has even been applied to 4 bits with only 16 possible valu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
