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In computer science, a container is a class or a data structure [1] [2] whose instances are collections of other objects. In other words, they store objects in an organized way that follows specific access rules. The size of the container depends on the number of objects (elements) it contains.
When data objects are stored in an array, individual objects are selected by an index that is usually a non-negative scalar integer. Indexes are also called subscripts. An index maps the array value to a stored object. There are three ways in which the elements of an array can be indexed: 0 (zero-based indexing)
A typical alternative for dense array storage is to use Iliffe vectors, which typically store pointers to elements in the same row contiguously (like row-major order), but not the rows themselves. They are used in (ordered by age): Java, [14] C#/CLI/.Net, Scala, [15] and Swift.
This comparison of programming languages (array) compares the features of array data structures or matrix processing for various computer programming languages. Syntax [ edit ]
For example, in the Pascal programming language, the declaration type MyTable = array [1..4,1..2] of integer, defines a new array data type called MyTable. The declaration var A: MyTable then defines a variable A of that type, which is an aggregate of eight elements, each being an integer variable identified by two indices.
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 ...
Boxing's most prominent use is in Java where there is a distinction between reference and value types for reasons such as runtime efficiency and syntax and semantic issues. In Java, a LinkedList can only store values of type Object. One might desire to have a LinkedList of int, but this is not directly possible.
In computer programming, a collection is an abstract data type that is a grouping of items that can be used in a polymorphic way. Often, the items are of the same data type such as int or string . Sometimes the items derive from a common type; even deriving from the most general type of a programming language such as object or variant .