# Use of Constants

Most of the macro function parameters can take numeric constants or expressions evaluating to a numeric constant (macro functions operating on strings can take string constants).

In macro functions performing record-by-record operations (for example, adding two numeric columns), using a constant is equivalent to specifying a column containing that constant value in each row. Essentially, when a constant is provided as an input parameter, the constant is expanded to same length as the input.

Some macro functions can take ASCII text strings and numeric constants. Parameters that can accept both numeric constants and ASCII text strings are noted in the "Parameters" section of each macro function.

Examples are provided in the following table.

Function Definition | How the Constant Is Interpreted |
---|---|

`PERCENT_UTILIZ = (CURR_BAL*100)/ CREDIT_LIM` |
The constant `100` is interpreted as a column
containing the same number of rows as the column `CURR_BAL` ,
with each row containing the constant `100` . The derived
field `PERCENT_UTILIZ` will contain each value of `CURR_BAL`
multiplied by `100` and divided by each value of `CREDIT_LIM` . |

`NAME = STRING_CONCAT ("Mr. ", LAST_NAME)` |
The constant `"Mr."` is interpreted
as a column containing the same number of rows as the column `LAST_NAME` ,
with each row containing the constant `"Mr."` .
The derived field `NAME` will contain each of the text
strings in `LAST_NAME` prefaced by `"Mr."` . |