Search results
Results from the WOW.Com Content Network
So, PHP can have non-consecutively numerically indexed arrays. The keys have to be of integer (floating point numbers are truncated to integer) or string type, while values can be of arbitrary types, including other arrays and objects. The arrays are heterogeneous: a single array can have keys of different types.
In object-oriented languages, string functions are often implemented as properties and methods of string objects. In functional and list-based languages a string is represented as a list (of character codes), therefore all list-manipulation procedures could be considered string functions.
In the Java virtual machine, internal type signatures are used to identify methods and classes at the level of the virtual machine code. Example: The method String String. substring (int, int) is represented in bytecode as Ljava / lang / String. substring (II) Ljava / lang / String;. The signature of the main method looks like this: [2]
Java [4] all non-object types, including (e.g.) booleans and numbers: all object types, including (e.g.) arrays C++: all data types, except reference types, array types and function types: arrays and functions C# [5] all non-object types, including structures and enumerations as well as primitive types: all object-types, including both classes ...
In C#, a class is a reference type while a struct (concept derived from the struct in C language) is a value type. [5] Hence an instance derived from a class definition is an object while an instance derived from a struct definition is said to be a value object (to be precise a struct can be made immutable to represent a value object declaring attributes as readonly [6]).
If a class does not specify its superclass, it implicitly inherits from java.lang.Object class. Thus all classes in Java are subclasses of Object class. If the superclass does not have a constructor without parameters the subclass must specify in its constructors what constructor of the superclass to use. For example:
Therefore, both Java and C# treat array types covariantly. For instance, in Java String [] is a subtype of Object [], and in C# string [] is a subtype of object []. As discussed above, covariant arrays lead to problems with writes into the array. Java [4]: 126 and C# deal with this by marking each array object with a type when it is created ...
An array data structure can be mathematically modeled as an abstract data structure (an abstract array) with two operations get(A, I): the data stored in the element of the array A whose indices are the integer tuple I. set(A, I, V): the array that results by setting the value of that element to V. These operations are required to satisfy the ...