STR will convert an integer expression into a string.
For example, STR(3) will become "3", or STR(333) will become "333".
Incidentally, this is the opposite of the VAL function, which converts a string into a number.
STR is also used in certain routines of the Hardware Library to designate that a series of bytes should be read or written to a string.
Also in the following case the STR function is implied and is not required.
bstring = 333 + " sent" ' will save the ASCI string "333 sent" into b$
The implied STR will work for simple expressions, but anything complex should use STR(), this would include any function call, array element fetches.
For floating point numbers use SPRINTF.