Rather than writing multiple instructions every time you want to find the maximum of a group of three
numbers, you can use a built-in function that does the calculation for you and returns the maximum
number. The function is called MAX, and you can use it as follows:
MAX(number1,number2,number3,....)
To find the maximum of 45, -2, number, and 199 and put the maximum into the symbol biggest, write the
following instruction:
biggest = MAX(45,-2,number,199)
Built-In Functions
More than 50 functions are built into the language processor. The built-in functions fall into the following
categories:
vArithmetic functions
Evaluate numbers from the argument and return a particular value.
vComparison functions
Compare numbers, or strings, or both and return a value.
vConversion functions
Convert one type of data representation to another type of data representation.
vFormatting functions
Manipulate the characters and spacing in strings supplied in the argument.
vString manipulating functions
Analyze a string supplied in the argument (or a variable representing a string) and return a particular
value.
vMiscellaneous functions
Do not clearly fit into any of the other categories.
The following tables briefly describe the functions in each category. For a complete description of these
functions, see Chapter 14, “Functions,” on page 171.
/***************************** REXX **********************************/
/* This program receives three numbers as arguments 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
Figure 27. Finding a Maximum Number
Using Functions
52 CICS TS for VSE/ESA: REXX Guide