A.3 Obsolescent Language Features in Fortran 90

Fortran 90 did not delete any of the features in FORTRAN 77, but some FORTRAN 77 features were identified as obsolescent.

Other methods are suggested to achieve the functionality of the following obsolescent features:

• Alternate return (labels in an argument list)

  To replace this functionality, it is recommended that you use an integer variable to return a value to the calling program, and let the calling program test the value and perform operations, using a computed GO TO statement (see Section 7.1.2) or CASE construct (see Section 7.3).

• Arithmetic IF

  To replace this functionality, it is recommended that you use an IF statement or construct (see Section 7.7).

• ASSIGN and assigned GO TO statements

  These statements are usually used to simulate internal procedures (see Section 8.7), which can now be coded directly.

• Assigned FORMAT specifier (label of a FORMAT statement assigned to an integer variable)

  To replace this functionality, it is recommended that you use character expressions to define format specifications (see Section 11.1).

• Branching to an END IF statement from outside its IF block

  To replace this functionality, it is recommended that you branch to the statement following the END IF statement (see Section 7.7.1).

• H edit descriptor

  To replace this functionality, it is recommended that you use the character constant edit descriptor (see Section 11.4).

• PAUSE statement

  To replace this functionality, it is recommended that you use a READ statement that awaits input data (see Section 10.3).

• Real and double precision DO control variables and DO loop control expressions

  To replace this functionality, it is recommended that you use integer DO variables and expressions (see Section 7.5).

• Shared DO termination and termination on a statement other than END DO or CONTINUE

  To replace this functionality, it is recommended that you use an END DO statement (see Section 7.5.1) or a CONTINUE statement (see Section 7.4).