|
Heap Pollution
In the Java programming language, heap pollution is a situation that arises when a variable of a parameterized type refers to an object that is not of that parameterized type. This situation is normally detected during compilation and indicated with an unchecked warning. Later, during runtime heap pollution will often cause a ClassCast Exception. Heap pollution in Java can occur when type arguments and variables are not reified at run-time. As a result, different parameterized types are implemented by the same class or interface Interface or interfacing may refer to: Academic journals * ''Interface'' (journal), by the Electrochemical Society * '' Interface, Journal of Applied Linguistics'', now merged with ''ITL International Journal of Applied Linguistics'' * '' Inter ... at run time. All invocations of a given generic type declaration share a single run-time implementation. This results in the possibility of heap pollution. Under certain conditions, a variable o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Programming
Java is a high-level, general-purpose, memory-safe, object-oriented programming language. It is intended to let programmers ''write once, run anywhere'' ( WORA), meaning that compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax of Java is similar to C and C++, but has fewer low-level facilities than either of them. The Java runtime provides dynamic capabilities (such as reflection and runtime code modification) that are typically not available in traditional compiled languages. Java gained popularity shortly after its release, and has been a popular programming language since then. Java was the third most popular programming language in according to GitHub. Although still widely popular, there has been a gradual decline in use of Java in recent years with other langu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Management
Memory management (also dynamic memory management, dynamic storage allocation, or dynamic memory allocation) is a form of Resource management (computing), resource management applied to computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is critical to any advanced computer system where more than a single Process (computing), process might be underway at any time. Several methods have been devised that increase the effectiveness of memory management. Virtual memory systems separate the memory addresses used by a process from actual physical addresses, allowing separation of processes and increasing the size of the virtual address space beyond the available amount of Random-access memory, RAM using paging or swapping to secondary storage. The quality of the virtual memory manager can have an extensive effect on overall system C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Syntax
The syntax of Java is the set of rules defining how a Java program is written and interpreted. The syntax is mostly derived from C and C++. Unlike C++, Java has no global functions or variables, but has data members which are also regarded as global variables. All code belongs to classes and all values are objects. The only exception is the primitive data types, which are not considered to be objects for performance reasons (though can be automatically converted to objects and vice versa via autoboxing). Some features like operator overloading or unsigned integer data types are omitted to simplify the language and avoid possible programming mistakes. The Java syntax has been gradually extended in the course of numerous major JDK releases, and now supports abilities such as generic programming and anonymous functions (function literals, called lambda expressions in Java). Since 2017, a new JDK version is released twice a year, with each release improving the language ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compile Time
In computer science, compile time (or compile-time) describes the time window during which a language's statements are converted into binary instructions for the processor to execute. The term is used as an adjective to describe concepts related to the context of program compilation, as opposed to concepts related to the context of program execution ( run time). For example, ''compile-time requirements'' are programming language requirements that must be met by source code before compilation and ''compile-time properties'' are properties of the program that can be reasoned about during compilation. The actual length of time it takes to compile a program is usually referred to as ''compilation time''. Overview Most compilers have at least the following compiler phases (which therefore occur at compile-time): syntax analysis, semantic analysis, and code generation. During optimization phases, constant expressions in the source code can also be evaluated at compile-time usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type System
In computer programming, a type system is a logical system comprising a set of rules that assigns a property called a ''type'' (for example, integer, floating point, string) to every '' term'' (a word, phrase, or other set of symbols). Usually the terms are various language constructs of a computer program, such as variables, expressions, functions, or modules. A type system dictates the operations that can be performed on a term. For variables, the type system determines the allowed values of that term. Type systems formalize and enforce the otherwise implicit categories the programmer uses for algebraic data types, data structures, or other data types, such as "string", "array of float", "function returning boolean". Type systems are often specified as part of programming languages and built into interpreters and compilers, although the type system of a language can be extended by optional tools that perform added checks using the language's original type synta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Runtime (program Lifecycle Phase)
Execution in computer engineering, computer and software engineering is the process by which a computer or virtual machine interprets and acts on the instructions of a computer program. Each instruction of a program is a description of a particular action which must be carried out, in order for a specific problem to be solved. Execution involves repeatedly following a "Instruction cycle, fetch–decode–execute" cycle for each instruction done by the control unit. As the executing machine follows the instructions, specific effects are produced in accordance with the Formal semantics of programming languages, semantics of those instructions. Programs for a computer may be executed in a Batch processing, batch process without human interaction or a User (computing), user may type Command (computing), commands in an Session (computer science), interactive session of an Interpreter (computing), interpreter. In this case, the "commands" are simply program instructions, whose executio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Conversion
In computer science, type conversion, type casting, type coercion, and type juggling are different ways of changing an expression from one data type to another. An example would be the conversion of an integer value into a floating point value or its textual representation as a string, and vice versa. Type conversions can take advantage of certain features of type hierarchies or data representations. Two important aspects of a type conversion are whether it happens ''implicitly'' (automatically) or ''explicitly'', and whether the underlying data representation is converted from one representation into another, or a given representation is merely ''reinterpreted'' as the representation of another data type. In general, both primitive and compound data types can be converted. Each programming language has its own rules on how types can be converted. Languages with strong typing typically do little implicit conversion and discourage the reinterpretation of representations, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exception Handling
In computing and computer programming, exception handling is the process of responding to the occurrence of ''exceptions'' – anomalous or exceptional conditions requiring special processing – during the execution of a program. In general, an exception breaks the normal flow of execution and executes a pre-registered ''exception handler''; the details of how this is done depend on whether it is a hardware or software exception and how the software exception is implemented. Exceptions are defined by different layers of a computer system, and the typical layers are CPU-defined interrupts, operating system (OS)-defined signals, programming language-defined exceptions. Each layer requires different ways of exception handling although they may be interrelated, e.g. a CPU interrupt could be turned into an OS signal. Some exceptions, especially hardware ones, may be handled so gracefully that execution can resume where it was interrupted. Definition The definition of an excep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reification (computer Science)
In computer science, reification is the process by which an abstract idea about a computer program, program is turned into an explicit data model or other object created in a programming language. A computable/addressable object—a ''resource''—is created in a system as a proxy for a non computable/addressable object. By means of reification, something that was previously implicit, unexpressed, and possibly inexpressible is explicitly formulated and made available to conceptual (logical or computational) manipulation. Informally, reification is often referred to as "making something a first-class citizen" within the scope of a particular system. Some aspect of a system can be reified at ''language design time'', which is related to Reflection (computer science), reflection in programming languages. It can be applied as a stepwise refinement at ''system design time''. Reification is one of the most frequently used techniques of conceptual analysis and knowledge representation. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Implementation (computer Science)
Implementation is the realization of an application, execution of a plan, idea, model, design, specification, standard, algorithm, policy, or the administration or management Management (or managing) is the administration of organizations, whether businesses, nonprofit organizations, or a Government agency, government bodies through business administration, Nonprofit studies, nonprofit management, or the political s ... of a process or objective. Industry-specific definitions Information technology In the information technology industry, implementation refers to the post-sales process of guiding a client from purchase to use of the software or hardware that was purchased. This includes requirements analysis, scope analysis, customizations, systems integrations, user policies, user training and delivery. These steps are often overseen by a project manager using project management methodologies. Software Implementations involve several professionals that are relati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interface (Java)
An interface in the Java programming language is an abstract type that is used to declare a behavior that classes must implement. They are similar to protocols. Interfaces are declared using the interface keyword, and may only contain method signature and constant declarations (variable declarations that are declared to be both static and final). All methods of an Interface do not contain implementation (method bodies) as of all versions below Java 8. Starting with Java 8, default and static methods may have implementation in the interface definition. Then, in Java 9, private and private static methods were added. At present, a Java interface can have up to six different types. Interfaces cannot be instantiated, but rather are implemented. A class that implements an interface must implement all of the non-default methods described in the interface, or be an abstract class. Object references in Java may be specified to be of an interface type; in each case, they must either be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Generics In Java
Generics are a facility of generic programming that were added to the Java programming language in 2004 within version J2SE 5.0. They were designed to extend Java's type system to allow "a type or method to operate on objects of various types while providing compile-time type safety". The aspect '' compile-time type safety'' required that parametrically polymorphic functions are not implemented in the Java virtual machine, since type safety is impossible in this case. The Java collections framework supports generics to specify the type of objects stored in a collection instance. In 1998, Gilad Bracha, Martin Odersky, David Stoutamire and Philip Wadler created Generic Java, an extension to the Java language to support generic types. Generic Java was incorporated in Java with the addition of wildcards. Hierarchy and classification According to ''Java Language Specification'': *A type variable is an unqualified identifier. Type variables are introduced by generic class declarati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
