RETAIN$ function

Purpose | Return a string containing only the characters contained in a specified match string. All other characters are removed..
Syntax | sResult$ = RETAIN$(mainstr$, [ANY] matchstr$)
Remarks | RETAIN$ returns a string consisting of zero or more copies of the complete expression matchstr$ which are found in mainstr$. All other characters are removed.
ANY | If the ANY option is included, matchstr$ specifies a list of single characters to be retained, if they are found in mainstr$.
Restrictions | If matchstr$ is an empty string, RETAIN$ returns an empty string.
See also | EXTRACT$, REMAIN$, REMOVE$, REPLACE
Example | a$ ="<p>1234567890<ak;lk;l>1234567890</p>" b$ = RETAIN$(a$, ANY "<;/p>") c$ = RETAIN$(a$, ANY "0123456789")
Result | b$ contains "<p><;;></p>" c$ contains "12345678901234567890"