Length constant—J

Use this constant to reserve storage for the length of a DXD, class, or DSECT. The assembler fills the field with binary zeros, and the length is entered into this space by the linker. This constant is only available if the GOFF option is specified.

In the following example, the value at A is the length of CLASS. 
A        DC              J(CLASS)

The DXD or DSECT names referenced in the J-type length constant need not be previously defined.

Table 1. J length constants
Subfield Value Example Result
1. Duplication factor Allowed    
2. Type J    
3. Type Extension D    
4. Program type Allowed    
5. Modifiers      

   Length:

J-type: 2 to 4 bytes,
        or 8
JD-type: 2 to 4 bytes,
        or 8
(no bit length)

    

      Implicit length:
      (Length modifier
      not present)

J-type: 4 bytes
JD-type: 8 bytes

    

      Alignment:
      (Length modifier
      not present)

J-type: Fullword
JD-type: Doubleword

    

   Scale:

 Not allowed    

   Exponent:

 Not allowed    
6. Nominal value      

   Represented by:

A single DXD, class,
or DSECT name

 
DC  J(CLASS)
  

   Enclosed by:

 Parentheses    

   Exponent allowed:

 No    

      Number of values
      per operand:

 
Multiple

    

   Padding:

 None.    

      Truncation of
      assembled value:

 
At left

    
Parent topic: Offset and length constants