STOP Statement STOP statement simply terminates the execution of the program and returns
control to the operating system. Its general form is:
STOP ' character constant '
The character constant (which must be a literal and not named constant) is
optional: if present its value is "made available" to the user; usually it the
message appears on your terminal. For compatibility with Fortran66 it is
possible to use a string of one to five decimal digits instead of the character
constant.
Ideally a program should only return control to the operating system from one
point, the end of the main program, where the END statement does all that is
necessary. In practice, even in the best-planned programs, situations can arise which
make it pointless to continue. If these are detected in the main program there is
always the option of jumping to the END statement, but within procedures there may
be no choice but to use a STOP statement.
