Search results
Results from the WOW.Com Content Network
In computer programming, operator overloading, sometimes termed operator ad hoc polymorphism, is a specific case of polymorphism, where different operators have different implementations depending on their arguments. Operator overloading is generally defined by a programming language, a programmer, or both.
When not overloaded, for the operators &&, ||, and , (the comma operator), there is a sequence point after the evaluation of the first operand. Most of the operators available in C and C++ are also available in other C-family languages such as C# , D , Java , Perl , and PHP with the same precedence, associativity, and semantics.
Specifically, the set of declarations discovered during the ADL process, and considered for resolution of the function name, is the union of the declarations found by normal lookup with the declarations found by looking in the set of namespaces associated with the types of the function arguments.
Assignment operators (+=, *= etc.) are combinations of a binary operator and the assignment operator (=) and will be evaluated using the ordinary operators, which can be overloaded. Cast operators (()) cannot be overloaded, but it is possible to define conversion operators.
However, there is no delete operator due to garbage collection mechanisms in Java, and there are no operations on pointers since Java does not support them. Another difference is that Java has an unsigned right shift operator (>>>), while C's right shift operator's signedness is type-dependent. Operators in Java cannot be overloaded.
An operator, defined by the language, can be overloaded to behave differently based on the type of input. Some languages (e.g. C, C++ and PHP) define a fixed set of operators, while others (e.g. Prolog, [6] Seed7, [7] F#, OCaml, Haskell) allow for user-defined operators.
Almost all operators can be overloaded for user-defined types, with a few notable exceptions such as member access (. and .*) and the conditional operator. The rich set of overloadable operators is central to making user-defined types in C++ seem like built-in types.
Operator overloading provides more than an aesthetic benefit when the language allows operators to be invoked implicitly in some circumstances. For example, this is the case with to_s operator in Ruby, which returns a string representation of an object.