Open Watcom FORTRAN 77 Language Reference

Assignment Statements
While the variable i is defined with a statement label, it should not be used in any other way other than in
an assigned GO TO statement. Consider the following example.
Example:
10 ASSIGN 10 TO I
* Illegal use of an ASSIGNed variable
PRINT *, I
The output produced by the PRINT statement is not the integer 10. Its value is undefined and should be
treated that way.
8.5 Character Assignment
The form of a character assignment statement is
v = e
where:
v
e
is a character variable name, character array element, or character substring.
is a character expression.
The following are examples of character assignment statements.
CHARACTER*20 C,D(5)
C=’ABCDEF’
C(3:5)=’XYZ’
D(5)(14:15)=’12’
Executing a character assignment statement causes the evaluation of the character expression e and the
definition of v with the result.
None of the character positions defined in v may be referenced in e. The following example is illegal
since the 4th and 5th character positions of A appear on the left and right hand side of the equal sign.
Example:
* Illegal character assignment.
CHARACTER*10 A,B*5
A(2:6) = A(4:5) // B
The length of v and e may be different. If the length of v is less than the length of e then the assignment
has the effect of truncating e from the right to the length of v. If the length of v is greater than the length
of e, the value assigned to v is the value of e padded on the right with blanks to the length of v.
Character Assignment 189