This REXX program receives three numbers from the user, compares the numbers to determine which is greatest, and returns the greatest number. It uses IF/THEN logic to compare the numbers and assign the greatest to a variable, which is then returned.

1. |
| /***************************** REXX ********************************/|
| /* This exec receives three numbers from a user and analyzes which */|
| /* number is the greatest. */|
| /*******************************************************************/|
| |
| PARSE ARG number1, number2, number3 . |
| |
| IF number1 > number2 THEN |
| IF number1 > number3 THEN |
| greatest = number1 |
| ELSE |
| greatest = number3 |
| ELSE |
| IF number2 > number3 THEN |
| greatest = number2 |
| ELSE |
| greatest = number3 |
| |
| RETURN greatest |
|
Possible Solution __________________________________________________
| |
| |
| /**************************** REXX *********************************/|
| /* This exec tests the length of a name for a data set member. If */|
| /* the name is longer than 8 characters, the exec truncates the */|
| /* extra characters and sends the user a message indicating the */|
| /* shortened member name. */|
| /*******************************************************************/|
| SAY 'Please enter a member name.' |
| PULL membername |
| |
| IF LENGTH(membername) > 8 THEN /* Name is longer than 8 characters*/|
| DO |
| membername = SUBSTR(membername,1,8) /* Shorten the name to */|
| /* the first 8 characters*/|
| SAY 'The member name you entered was too long.' |
| SAY membername 'will be used.' |
| END |
| ELSE NOP
CALL subroutine_name argument1, argument2,...
x = function(argument1, argument2,...)

2. |
| /******************************* REXX ******************************/|
| /* This exec receives a calculated value from an internal */|
| /* subroutine and displays that value. */|
| /*******************************************************************/|
| |
| number1 = 5 |
| number2 = 10 |
| CALL subroutine |
| SAY answer /* Displays 15 */|
| EXIT |
| |
| subroutine: |
| answer = number1 + number2 |
| RETURN |
|
/******************************* REXX ******************************/|
| /* This exec uses a PROCEDURE instruction to protect the variables */|
| /* within its subroutine. */|
| /*******************************************************************/|
| number1 = 10 |
| CALL subroutine |
| SAY number1 number2 /* displays 10 NUMBER2 */|
| EXIT |
| |
| subroutine: PROCEDURE |
| number1 = 7 |
| number2 = 5 |
| RETURN
|
| /****************************** REXX *******************************/|
| /* This exec uses a PROCEDURE instruction with the EXPOSE option to*/|
| /* expose one variable, number1, in its subroutine. The other */|
| /* variable, number2, is set to null and displays its name in */|
| /* uppercase. */|
| /*******************************************************************/|
| number1 = 10 |
| CALL subroutine |
| SAY number1 number2 /* displays 7 NUMBER2 */|
| EXIT |
| |
| subroutine: PROCEDURE EXPOSE number1 |
| number1 = 7 |
| number2 = 5 |
| RETURN

3. |
| /****************************** REXX *******************************/|
| /* This exec receives a calculated value from an internal */|
| /* function and displays that value. */|
| /*******************************************************************/|
| |
| number1 = 5 |
| number2 = 10 |
| SAY add() /* Displays 15 */|
| SAY answer /* Also displays 15 */|
| EXIT |
| |
| add: |
| answer = number1 + number2 |
| RETURN answer