Editing Object REXX (section)

=== Everything is an Object ===
While classic Rexx follows the "Everything is a String" philosophy and has [[String (computer science)|string]] as its only data type, ooRexx considers everything as objects, including non-string objects such as arrays, streams and many more. Objects are manipulated using methods instead of traditional functions. 

In ooRexx, a string variable is a reference to a string object and does not need to be declared, which reduces the effort for programmers compared to [[Type system|strictly typed languages]].<ref>{{Cite journal |last1=Stefik |first1=Andreas |last2=Siebert |first2=Susanna |date=2013 |title=An empirical investigation into programming language syntax. |url=https://dl.acm.org/doi/10.1145/2534973 |journal=ACM Transactions on Computing Education |volume=13 |issue=4 |pages=1–40 |doi=10.1145/2534973|url-access=subscription }}</ref> A string object can be of any length and contain any characters, including numerical values. It is therefore possible to change numerical values with string manipulations and methods of the <code>String</code> class. In addition, a string variable can contain any type of expression, including executable instructions, which can be evaluated or executed with the <code>INTERPRET</code> keyword instruction.<ref name=":2" /><syntaxhighlight lang="oorexx" style="background-color: #ffffff; !important" line="1">
a = 2                               /* string with numerical value      */
a = a || '0'                        /* resulting string: 20             */

str = "do i = 1 to "a"; say i; end" /* string contains loop instruction */
interpret str                       /* interpret string: counts to 20   */
</syntaxhighlight>