Commodore Plus 4 - Page 74

62 The BASIC Language
3. The length of the substring can be any length. If it is greater than the number
of characters after the start position in the master string, the entire rest of the
string is returned. The length can be omitted. If it is omitted, all of the string after
the start position is returned.
MID$ can also be used on the left side of an equation to replace a substring of a
given length within the master string.
Examples: PRINT MID$(''GRADUATE'',6,3)
ATE
10 INPUT "ENTER THE NEXT MODEL"; A$ Examines five char-
20 IP MID$(A$,6,5)<>"WAG0N" THEN END acters starting at
30 MID$(A$,6,5>"SEDAN": PRINT A$ character 6 for the
RUN string WAGON.
ENTER THE NEXT MODEL ? 4-DR WAGON WAGON is replaced
4-DR SEDAN by SEDAN.
PRINT MID$("R0CKETSHIP",7)
SHIP
MONITOR Abbr. mO
Leaves BASIC and goes to the built-in machine-language monitor. You can
use the 13 machine-language monitor commands to write and execute programs
in machine language. Return to BASIC from the monitor by typing X and
pressing the RETURN key. See Chapter 5 for more information on machine
language.
NEW Abbr. none
Erases the current program from memory. The program cannot be recalled
unless it is saved on tape or disk. (If you execute a NEW accidentally and want to
try to retrieve your program, see Chapter 3 for information on unNEWing.)
Always issue a NEW command before you start writing a new program to be sure
the program area of memory is clear. If you do not clear the memory, lines from
the previous program will mix with your current program.
NEXT Abbr. nE
Marks the closing bracket of a FOR loop. See FOR.