Array programming
Array programming languages (also known as vector or multidimensional languages) generalize operations on scalars to apply transparently to vectors, matrices, and higher dimensional arrays.
Overview
In scalar languages like Fortran, C, Pascal, Ada, etc. operations apply only to single values, so a+b expresses the addition of two numbers. In such languages adding two arrays requires indexing and looping:
FORTRAN 77
DO 10 I = 1, N
DO 10 J = 1, N
10 A(I,J) = A(I,J) + B(I,J)
C
for ( i=0; i<n; i++) {
for ( j=0; j<n; j++) {
a[i][j] = a[i][j]+b[i][j];
}
}
This need to loop and index to perform operations on arrays is both tedious and error prone.
In array languages, operations are generalized to apply to both scalars and arrays. Thus, a+b expresses the sum of two scalars if a and b are scalars, or the sum of two arrays if they are arrays. When applied to arrays, the operations act on corresponding elements as illustrated in the loops above. Indeed, when the an array language compiler/interpreter encounters an statement like:
A := A + B
and A and B are two dimensional arrays, it generates code that is effectively the same as the C loops shown above. An array language, therefore, simplifies programming.
Examples
Some examples of array programming languages: