Local and global names

The names used in nested programs may be classified as "local" and "global" names.

Local names

Local names are valid only within the program in which the associated data is described. Most of the names that are local as standard can be declared as global. The following names are always local:

• paragraph-names

• section-names

Global names

Global names are valid not only in the program in which they are defined but also in that program’s contained programs.
The following name types are always global:

• Names defined in the CONFIGURATION SECTION:

  computer-name
  alphabet-names
  class-names
  condition-names (SPECIAL NAMES paragraph)
  mnemonic-names
  symbolic characters
  CURRENCY SIGN character
  DECIMAL-POINT

• COBOL special registers:

  TALLY
  PRINT-SWITCH
  SORT registers
  RETURN-CODE

The following name types are local as standard and can be explicitly defined as global in nested programs:

• condition-names

• data-names

• file-names

• index-names

• record-names

• report-names

• type-names

Definition of a name as global is performed using the GLOBAL clause (see section "GLOBAL clause" of chapter "File description" and section "GLOBAL clause" of chapter "Data description entry").

In the case of type names the GLOBAL phrase refers to the definition of the type and not to the data description generated with the aid of the type definition.

Determining the valid name

When a name is referenced, the valid name is selected from the sum total of all the names defined in the nested program, in accordance with the following rules of precedence:

1. The referenced name is defined in the same program.

2. If 1) does not apply, the referenced name is defined as a global name in the directly superordinate (next outer) program.

3. If neither 1) nor 2) applies, the referenced name is defined as a global name in the indirectly superordinate program.

   Condition 3) is checked until the data description entry of the referenced name is found in one of the other indirectly superordinate programs, possibly in the outermost containing program.

Example 12-6

 

Example 12-7

PROGRAM-ID. A-PROG.
...
01 T1 TYPEDEF STRONG GLOBAL. 
   02 NAME PIC X(30).
   02 STREET PIC X(80).
...
01 A1 TYPE T1.                1)
01 B1 TYPE T1 GLOBAL.
...
PROGRAM-ID. B-PROG.
...
01 T1 TYPEDEF STRONG.         2)
   02 SUBSTRUKTUR.
     05 NAME-3 PIC X(30).
     05 STREET-3 PIC X(80).
...
01 C1 TYPE T1.                3)
...
MOVE B1 TO C1.                4)
...
END PROGRAM B-PROG.
END PROGRAM A-PROG.

1. Uses type definition T1 from A-PROG;
   Definition A1 is local in A-Prog, definition B1 is global
2. Type T1 is local in B-PROG
3. Uses type definition T1 from B-PROG
4. Allocation is permissible as T1 in A-PROG is equivalent to T1 in B-PROG