BOUND

Return the declared length of an array dimension.

n = BOUND(array(), dim)

array() - array name with empty parentheses dim - 1-based dimension; 0 when the dimension is out of range

See also DIM, ARRAY.

Example:

DIM A(10)
PRINT BOUND(A(), 1)     ' 11

Source: docs/help/bound.txt inmmcore. On the computer, typeHELP BOUND.