Arithmetic IF
Encyclopedia
The arithmetic IF statement has been for several decades a three-way arithmetic conditional statement, starting from the very early version (1957) of Fortran
, and including FORTRAN IV, FORTRAN 66 and FORTRAN 77. Unlike the logical IF statements seen in other languages, the Fortran statement defines three different branches depending on whether the result of an expression was negative, zero, or positive, in said order, written as:
IF (expression) negative,zero,positive
While it was originally the only kind of IF statement provided in Fortran, the feature was used less and less frequently after the more powerful logical IF statements were introduced, and was finally labeled obsolescent
in Fortran 90.
The arithmetic IF was also used in FOCAL.
Fortran
Fortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...
, and including FORTRAN IV, FORTRAN 66 and FORTRAN 77. Unlike the logical IF statements seen in other languages, the Fortran statement defines three different branches depending on whether the result of an expression was negative, zero, or positive, in said order, written as:
IF (expression) negative,zero,positive
While it was originally the only kind of IF statement provided in Fortran, the feature was used less and less frequently after the more powerful logical IF statements were introduced, and was finally labeled obsolescent
Obsolescence
Obsolescence is the state of being which occurs when an object, service or practice is no longer wanted even though it may still be in good working order. Obsolescence frequently occurs because a replacement has become available that is superior in one or more aspects. Obsolete refers to something...
in Fortran 90.
The arithmetic IF was also used in FOCAL.