ensure Variable Modifier

Format

ensure numeric variable_name1ʃ, ... , variable_nameNʅ;

Description

The ensure variable modifier allows for the conditional creation of numeric variables in the PROC GLOBAL section of logic. One or more variable names are specified, and if the name of the variable exists (because of being declared previously in logic, or defined in a dictionary), then it will not be created. If it does not exist, a temporary variable is created just as if it were a declared numeric variable. The initial value of the variable is 0.

This statement is useful when working with applications that reuse blocks of logic with different dictionaries. If a certain routine depends on a dictionary variable, you can use this statement to ensure that the logic compiles without issue. It is important to make sure that your logic works regardless of whether the variable is defined in a dictionary or from the ensure statement.

In versions of CSPro prior to 7.2, you could simulate the behavior of ensure by using set implicit mode.

Example

PROC GLOBAL

ensure numeric SUPERVISOR_CODE;

PROC DATA_TRANSMISSION

// assuming that 0 is never a valid value for SUPERVISOR_CODE, then
// you could have two synchronization routines in your code, one for
// surveys where there are supervisors (and SUPERVISOR_CODE is defined
// in a dictionary), and another for surveys where interviewers directly
// send data to headquarters

if SUPERVISOR_CODE = 0 then
SyncWithHeadquarters();

else
SyncWithSupervisor();

endif;