Search results
Results From The WOW.Com Content Network
A null pointer has a value reserved for indicating that the pointer does not refer to a valid object. Null pointers are routinely used to represent conditions such as the end of a list of unknown length or the failure to perform some action; this use of null pointers can be compared to nullable types and to the Nothing value in an option type.
Classes in Java can only inherit from one class. A class can be derived from any class that is not marked as final. Inheritance is declared using the extends keyword. A class can reference itself using the this keyword and its direct superclass using the super keyword.
Cell of SQL table row in INSERT INTO statement (cell value) Portion of IDL operation declaration, typically related to declaration of an operation type code, parameter list, operation return value, or list of exceptions Information Object Set (IOS) (collection of Information Objects) Completely defined SQL table (collection of rows) (see Note 1)
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 some programming language environments (at least one proprietary Lisp implementation, for example), [citation needed] the value used as the null pointer (called nil in Lisp) may actually be a pointer to a block of internal data useful to the implementation (but not explicitly reachable from user programs), thus allowing the same register to be used as a useful constant and a quick way of ...
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]
The technique is simply to allocate a table V storing the pairs (k i, v i) in some arbitrary order, and to write for each i in the cell T[k i] the position in V where key k i is stored, leaving the other cells of T uninitialized. This can be used to handle queries in the following fashion: when we look up cell T[k] for some k, we can check if T ...
In object-oriented (OO) and functional programming, an immutable object (unchangeable [1] object) is an object whose state cannot be modified after it is created. [2] This is in contrast to a mutable object (changeable object), which can be modified after it is created. [3]