Flow control : if / case

if ... elseif ... else ... endif

data AGE type I value '12'.

if AGE < 0.
  write 'Illegal value'.
elseif AGE >= 0 and AGE < 18.
  write 'Sorry, this is adult only.'.
else.
  write 'Hi, wellcome.'.
endif.

case ... when .... when others ... endcase

data S(2) value 'F'.

case S.                      " case sensitive
  when 'F'.
    write / 'Hi, girl.'.
  when 'M'.
    write / 'Hi, boy.'.
  when others.
    write / 'Who it is?'.
endcase.