### 11.5 LEAVE

         LEAVE var_list.

`LEAVE` prevents the specified variables from being reinitialized whenever a new case is processed.

Normally, when a data file is processed, every variable in the active dataset is initialized to the system-missing value or spaces at the beginning of processing for each case. When a variable has been specified on `LEAVE`, this is not the case. Instead, that variable is initialized to 0 (not system-missing) or spaces for the first case. After that, it retains its value between cases.

This becomes useful for counters. For instance, in the example below the variable `SUM` maintains a running total of the values in the `ITEM` variable.

         DATA LIST /ITEM 1-3.
         COMPUTE SUM=SUM+ITEM.
         PRINT /ITEM SUM.
         LEAVE SUM
         BEGIN DATA.
         123
         404
         555
         999
         END DATA.

Partial output from this example:

         123   123.00
         404   527.00
         555  1082.00
         999  2081.00

It is best to use `LEAVE` command immediately before invoking a procedure command, because the left status of variables is reset by certain transformations—for instance, `COMPUTE` and `IF`. Left status is also reset by all procedure invocations.