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Other languages provide only one-based array types, where each index starts at 1; this is the traditional convention in mathematics for matrices and mathematical sequences. A few languages, such as Pascal and Lua, support n-based array types, whose minimum legal indices are chosen by the programmer. The relative merits of each choice have been ...
More generally, there are d! possible orders for a given array, one for each permutation of dimensions (with row-major and column-order just 2 special cases), although the lists of stride values are not necessarily permutations of each other, e.g., in the 2-by-3 example above, the strides are (3,1) for row-major and (1,2) for column-major.
Functions involving two or more variables require multidimensional array indexing techniques. The latter case may thus employ a two-dimensional array of power[x][y] to replace a function to calculate x y for a limited range of x and y values. Functions that have more than one result may be implemented with lookup tables that are arrays of ...
In Lua, "table" is a fundamental type that can be used either as an array (numerical index, fast) or as an associative array. The keys and values can be of any type, except nil. The following focuses on non-numerical indexes. A table literal is written as { value, key = value, [index] = value, ["non id string"] = value }. For example:
In computer science, a dynamic array, growable array, resizable array, dynamic table, mutable array, or array list is a random access, variable-size list data structure that allows elements to be added or removed. It is supplied with standard libraries in many modern mainstream programming languages.
A multimap generalizes an associative array by allowing multiple values to be associated with a single key. [9] A bidirectional map is a related abstract data type in which the mappings operate in both directions: each value must be associated with a unique key, and a second lookup operation takes a value as an argument and looks up the key ...
For example, a two-dimensional array A with three rows and four columns might provide access to the element at the 2nd row and 4th column by the expression A[1][3] in the case of a zero-based indexing system. Thus two indices are used for a two-dimensional array, three for a three-dimensional array, and n for an n-dimensional array.
[2]: 113 [5] The vertical bar (also referred to as pipe) and space are also sometimes used. [2]: 113 Column headers are sometimes included as the first line, and each subsequent line is a row of data. The lines are separated by newlines. For example, the following fields in each record are delimited by commas, and each record by newlines: