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Depending on the environment, a warning, a fatal exception, or unpredictable behavior will occur if the program attempts to access an array element that is outside the range. In some programming languages, such as C, arrays have a fixed lower bound (zero) and will contain data at each position up to the upper bound (so an array with 5 elements ...
Some programming languages provide operations that return the size (number of elements) of a vector, or, more generally, range of each index of an array. In C and C++ arrays do not support the size function, so programmers often have to declare separate variable to hold the size, and pass it to procedures as a separate parameter. Elements of a ...
In addition to support for vectorized arithmetic and relational operations, these languages also vectorize common mathematical functions such as sine. For example, if x is an array, then y = sin (x) will result in an array y whose elements are sine of the corresponding elements of the array x. Vectorized index operations are also supported.
Given a function that accepts an array, a range query (,) on an array = [,..,] takes two indices and and returns the result of when applied to the subarray [, …,].For example, for a function that returns the sum of all values in an array, the range query (,) returns the sum of all values in the range [,].
The C++ Standard Library also supports for_each, [10] that applies each element to a function, which can be any predefined function or a lambda expression. While range-based for is only from the start to the end, the range or direction can be changed by altering the first two parameters.
For instance, within the loop a reference to element I of an array would likely employ the auxiliary variable (especially if it were held in a machine register), but if I is a parameter to some routine (for instance, a print-statement to reveal its value), it would likely be a reference to the proper variable I instead. It is best to avoid such ...
Function rank is an important concept to array programming languages in general, by analogy to tensor rank in mathematics: functions that operate on data may be classified by the number of dimensions they act on. Ordinary multiplication, for example, is a scalar ranked function because it operates on zero-dimensional data (individual numbers).
One technique for bounds-checking elimination is to use a typed static single assignment form representation and for each array to create a new type representing a safe index for that particular array. The first use of a value as an array index results in a runtime type cast (and appropriate check), but subsequently the safe index value can be ...