Open Watcom FORTRAN 77 Language Reference

Language Reference
Example:
SELECT CASE ( CH )
CASE ( ’a’ : ’z’ )
PRINT *, ’Lower case letter’
CASE ( ’A’ : ’Z’ )
PRINT *, ’Upper case letter’
CASE ( ’0’ : ’9’ )
PRINT *, ’Digit’
CASE DEFAULT
PRINT *, ’Special character’
END SELECT
In the above example, if the character CH is not a letter or digit then the CASE DEFAULT block is
executed.
The CASE DEFAULT statement is optional. If it is present and the case expression is out of range (i.e., no
CASE blocks are executed) then the CASE DEFAULT block is executed. If it is not present and the case
expression is out of range then execution continues with the first executable statement following the END
SELECT statement. The CASE DEFAULT block must follow all other CASE blocks.
Example:
SELECT CASE ( I )
CASE ( 1 )
Y = Y + X
X = X * 3.2
CASE ( 2 )
Z = Y**2 + X
CASE ( 3 )
Y = Y * 13. + X
X = X - 0.213
CASE ( 4 )
Z = X**2 + Y**2 - 3.0
Y = Y + 1.5
X = X * 32.0
CASE DEFAULT
PRINT *, ’CASE is not in range’
END SELECT
PRINT *, X, Y, Z
In order to retain compatibility with earlier versions of WATCOM FORTRAN 77 compilers, the
OTHERWISE statement may be used in place of the CASE DEFAULT statement.
For more information, see the chapter entitled "Program Structure Control Statements" on page 193.
138 SELECT Statement