Carbon/400
Sign in

docs RPG Reference

Specifying an Array in Calculations

Specifying an Array in Calculations

An entire array or individual elements in an array can be specified in calculation specifications. You can process individual elements like fields.

A noncontiguous array defined with the OVERLAY keyword cannot be used with the MOVEA operation or in the result field of a PARM operation.

To specify an entire array, use only the array name, which can be used as factor 1, factor 2, or the result field. The following operations can be used with an array name: ADD, Z-ADD, SUB, Z-SUB, MULT, DIV, SQRT, ADDDUR, SUBDUR, EVAL, EXTRCT, MOVE, MOVEL, MOVEA, MLLZO, MLHZO, MHLZO, MHHZO, DEBUG, XFOOT, LOOKUP, SORTA, PARM, DEFINE, CLEAR, RESET, CHECK, CHECKR, and SCAN.

Several other operations can be used with an array element only but not with the array name alone. These operations include but are not limited to: BITON, BITOFF, COMP, CABxx, TESTZ, TESTN, TESTB, MVR, DO, DOUxx, DOWxx, DOU, DOW, IFxx, WHENxx, WHEN, IF, SUBST, and CAT.

When specified with an array name without an index or with an asterisk as the index (for example, ARRAY or ARRAY(*)) certain operations are repeated for each element in the array. These are ADD, Z-ADD, EVAL, SUB, Z-SUB, ADDDUR, SUBDUR, EXTRCT, MULT, DIV, SQRT, MOVE, MOVEL, MLLZO, MLHZO, MHLZO and MHHZO. The following rules apply to these operations when an array name without an index is specified:

  • When factors 1 and 2 and the result field are arrays with the same number of elements, the operation uses the first element from every array, then the second element from every array until all elements in the arrays are processed. If the arrays do not have the same number of entries, the operation ends when the last element of the array with the fewest elements has been processed. When factor 1 is not specified for the ADD, SUB, MULT, and DIV operations, factor 1 is assumed to be the same as the result field.
  • When one of the factors is a field, a literal, or a figurative constant and the other factor and the result field are arrays, the operation is done once for every element in the shorter array. The same field, literal, or figurative constant is used in all of the operations.
  • The result field must always be an array.
  • If an operation code uses factor 2 only (for example, Z-ADD, Z-SUB, SQRT, ADD, SUB, MULT, or DIV may not have factor 1 specified) and the result field is an array, the operation is done once for every element in the array. The same field or constant is used in all of the operations if factor 2 is not an array.
  • Resulting indicators (positions 71 through 76) cannot be used because of the number of operations being processed.
  • In an EVAL expression, if any arrays on the right-hand side are specified without an index, the left-hand side must also contain an array without an index.

Note: When used in an EVAL operation %ADDR(arr) and %ADDR(arr(*)) do not have the same meaning. See %ADDR (Get Address of Variable) for more detail.

When coding an EVAL or a SORTA operation, built-in function %SUBARR(arr) can be used to select a portion of the array to be used in the operation. See %SUBARR (Set/Get Portion of an Array) for more detail.