The dyadic system function ŒTR translates character data from internal (ŒAV) representation to the external representation used in non-APL applications, and vice versa. Normally, this translation is done automatically when text data is transferred to/from APL, but sometimes you may need to translate data explicitly.
The right argument is a character array of any size and shape. The left argument is an integer code indicating in which direction you wish to translate. This is 1 for External (Extended ASCII) to Internal, and ¯1 for Internal to External. The result is a character array of the same size and shape as the right argument, with the characters translated as requested.
ŒAF 'hello' 232 229 236 236 239 ŒAF ¯1 ŒTR 'hello' 104 101 108 108 111