CASE

CASE statements are used for conditional execution of code in VPL programs.

CASE <expression> OF
<constant 1>,<constant 2>,<constant 3>:
   <statements>
<constant 1>..<constant 2>:
   <statements>
<constant 1>..<constant 2>,<constant 3>:
   <statements>
ELSE
   <statements>
END_CASE;

<expr> is an expression that evaluates to a number. If one of the <num> values has the same value as <expr>, that section of code will be executed.

If none of the <num> values match the <expr> value, the statements after the ELSE word are executed, and if no ELSE statement is found, the code after the END_CASE word will be executed.

The <expression> is limited to variables of SINT and INT types.

Example:

INCLUDE rtcu.inc
 
VAR
   a   : INT;
   str : STRING;
END_VAR;
 
PROGRAM test;
 
BEGIN
 
   CASE a OF
      -1    : str := "a is minus one";
      1     : str := "a is one";
      2..6  : str := "a is between two and six";
      7,9   : str := "a is either seven or nine";
   ELSE
      str := "a is something else...";
   END_CASE;
 
END;
 
END_PROGRAM;