Open Watcom FORTRAN 77 Language Reference

FORTRAN Statements
2.8 BLOCK DATA Statement
BLOCK DATA [sub]
where:
sub
is an optional symbolic name of the block data subprogram and must not be the name of an
external procedure, main program, common block, other block data subprogram, or any local
name in the block data subprogram.
The BLOCK DATA statement is used to define the start of a block data subprogram. A block data
subprogram is used to provide initial values for variables and array elements in named common blocks.
The only statements which are allowed to appear in a block data subprogram are:
1. IMPLICIT
2. PARAMETER
3. DIMENSION
4. COMMON
5. SAVE
6. EQUIVALENCE
7. DATA
8. STRUCTURE, END STRUCTURE
9. UNION, END UNION
10. MAP, END MAP
11. RECORD
12. END
13. type statements
Example:
BLOCK DATA INITCB
DIMENSION A(10), B(10)
COMMON /CB/ A, B
DATA A/10*1.0/, B/10*2.0/
END
In the above example, the arrays A and B in the named common block CB are initialized.
Notes:
1. More than one named common block may appear in a block data subprogram.
2. All entities of the named common block(s) must be specified.
3. Not all entities need be given initial values.
4. Only entities that appear in (or are associated, through the EQUIVALENCE statement, with
entries in) a named common block may be given initial values.
5. Only one unnamed block data subprogram may occur in an executable program.
BLOCK DATA Statement 21