In addition to its versatility, REXX has many other features, some of which are:
The REXX language is easy to read and write because many instructions are meaningful English words. Unlike some lower level programming languages that use abbreviations, REXX instructions are common words, such as SAY, PULL, IF...THEN...ELSE..., DO...END, and EXIT.
There are few rules about REXX format. You need not start an instruction in a particular column. You can skip spaces in a line or skip entire lines. You can have an instruction span of many lines, or have multiple instructions on one line. You need not predefine variables. You can type instructions in upper, lower, or mixed case. The few rules about REXX format are covered in section Syntax of REXX Instructions.
REXX supplies built-in functions that perform various processing, searching, and comparison operations for both text and numbers. Other built-in functions provide formatting capabilities and arithmetic calculations.
When a REXX program running in REXX/CICS encounters an error, REXX writes messages describing the error. You can also use the REXX TRACE instruction and the interactive debug facility to locate errors in programs.
The REXX/CICS product includes the REXX/CICS interpreter. When a REXX program runs, the interpreter directly processes each line. Languages that are not interpreted must be compiled into machine language and possibly link-edited before they are run.
REXX includes extensive parsing capabilities for character manipulation. This parsing capability lets you set up a pattern to separate characters, numbers, and mixed input.