By default, PROC FCMP passes arrays “by value” between routines. However, if an array is listed in the OUTARGS statement within the routine, the array is passed “by reference.”

This means that a modification to the formal parameter by the function modifies the array that is passed. Passing arrays by reference helps to efficiently pass large amounts of data between the function and the calling environment because the data does not need to be copied. The syntax for specifying a formal array has the following form:

function
name(numeric-array-parameter[*],
character-array-parameter[*] $);

You can pass DATA step temporary arrays to PROC FCMP routines.

You can resize arrays in PROC FCMP routines by calling the built-in CALL routine DYNAMIC_ARRAY. The syntax for this CALL routine has the following form:

call dynamic_array(array, new-dim1-size, ..., new-dimN-size);

SAS passes to the DYNAMIC_ARRAY CALL routine both the array that is to be resized and a new size for each dimension of the array. A dynamic array enables the routine to allocate the amount of memory that is needed, instead of having to create an array that is large enough to handle all possible cases.

Support for dynamic arrays is limited to PROC FCMP routines. When an array is resized, the array is available only in the routine that resized it. It is not possible to resize a DATA step array or to return a PROC FCMP dynamic array to a DATA step.