18.1General Description

The dimension-statement is used to reserve space for arrays. Unless declared otherwise, all array subscripts shall have a lower bound of zero and an upper bound of ten. Thus the default space allocation reserves space for 11 elements in one-dimensional arrays and 121 elements in two-dimensional arrays. By use of a dimension-statement, the subscript(s) of an array may be declared to have an upper bound other than ten. By use of an option-statement, the subscripts of all arrays may be declared to have a lower bound of one. The general syntactic form of the dimension-statement is DIM declaration, ..., declaration where each declaration has the form letter (integer) or letter (integer , integer) The general syntactic form of the option-statement is OPTION BASE n where n is either 0 or 1.

18.2 Syntax

            1. dimension-statement        = DIM array declaration (comma array-declaration)*
            2. array-declaration          = numeric-array-name left-parenthesis bounds right-parenthesis
            3. bounds                     = integer (comma integer)?
            4. option-statement           = OPTION BASE (0/1)
        

18.3 Examples

DIM A (6), B(10,10)

18.4 Semantics

Each array-declaration occurring in a dimension-statement declares the array named to be either one or two dimensional according to whether one or two bounds are listed for the array. In addition, the hounds specify the maximum values that subscript expressions for the array can have. The declaration for an array, if present at all, shall occur in a lower numbered line than any reference to an element of that array. Arrays that are not declared in any dimension-statement are declared implicitly to be one or two dimensional according to their use in the program, and to have subscripts with a maximum value of ten (see 7). The option-statement declares the minimum value for all array subscripts; if no option-statement occurs in a program, this minimum is zero. An option-statement, if present at all, must occur in a lower numbered line than any dimension-statement or any reference to an element of an array. If an option-statement specifies that the lower bound for array subscripts is one, the no dimens ion-statement in the program may specify an upper boun of zero. A program may contain at most one option-statement. If the execution of a program reaches a line containing a dimension-statement or an option-statement, then it shall proceed to the next line with no other effect. An array can be explicitly dimensioned only once.

18.5 Exceptions

None.