JSONNULL attribute

The JSONNULL attribute indicates if an item should be generated as a JSON null during the invocation of JSONPUTVALUE or JSONPUTMEMBER.

When JSONNULL is specified on a scalar, the scalar is generated as "null" if the item is a string equal to the null string ('') or a number equal to 0.

When JSONNULL is specified on a structure, the structure is generated as "null" if all its leaf elements are null.

When JSONNULL is specified on an array, any null elements in the array are generated as "null". and if all elements in the array are null, then the entire array is generated as "null".

For example, given the following code:

     dcl buffer     char(4096);
     dcl written    fixed bin(31);

     dcl elev(5) pic'99999V.99' static
           init( 1200, 0, 11500, 0, 11750 ) jsonnull;

     written = 0;
     written = jsonputmember( addr(buffer), stg(buffer), elev );

The output buffer will contain:

"ELEV":["01200.00",null,"11500.00",null,"11750.00"]

If all the elements in the array were 0, then the output buffer will contain:

"ELEV":null

If JSONNULL and JSONOMIT are both specified for a field, then JSONOMIT takes precedence.