Search results
Results From The WOW.Com Content Network
Nullable types are a feature of some programming languages which allow a value to be set to the special value NULL instead of the usual possible values of the data type.In statically typed languages, a nullable type is an option type, [citation needed] while in dynamically typed languages (where values have types, but variables do not), equivalent behavior is provided by having a single null ...
In object-oriented computer programming, a null object is an object with no referenced value or with defined neutral (null) behavior.The null object design pattern, which describes the uses of such objects and their behavior (or lack thereof), was first published as "Void Value" [1] and later in the Pattern Languages of Program Design book series as "Null Object".
A snippet of Java code with keywords highlighted in bold blue font. 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.
Null-restricted and Nullable types, and Null-restricted Objects: for example, using ? or ! after type declaration to say if null is allowed or not. Enhanced Primitive Boxing: for example, to allow code such as List<int>. Reified Generics: retaining actual type at runtime. These features will require both syntax and VM-level changes.
1.1 Java example. 2 Algebraic data types. Toggle Algebraic data types subsection. ... /* Non-nullary constructor */ public Example (final int data) {this. data = data;}}
Java does not have uninitialized variables. Fields of classes and objects that do not have an explicit initializer and elements of arrays are automatically initialized with the default value for their type (false for boolean, 0 for all numerical types, null for all reference types). [4]
In C, two null pointers of any type are guaranteed to compare equal. [3] Prior to C23, the preprocessor macro NULL was provided, defined as an implementation-defined null pointer constant in <stdlib.h>, [4] which in C99 can be portably expressed as ((void *)0), the integer value 0 converted to the type void* (see pointer to void type). [5]
Complete article "Java Singleton Pattern Explained" Four different ways to implement singleton in Java "Ways to implement singleton in Java" Book extract: Implementing the Singleton Pattern in C# by Jon Skeet; Singleton at Microsoft patterns & practices Developer Center; IBM article "Double-checked locking and the Singleton pattern" by Peter Haggar