Z1 ZIABCD (variable name too long)
TP TO (variable names cannot be reserved words)
PSTG$ RGOTO (variable names cannot contain reserved words)
COUNT
ASSIGNING VARIABLES WITH A LET OR ASSIGNMENT STATEMENT
Besides having values assigned to variables with an input statement, you can also set the value of a
variable with a LET or assignment statement.
Try the following examples:
A=5
PRINT A, A*2
5 10
LET Z=7
PRINT Z, Z-A
7 2
As you will notice from the examples, the "LET" is optional in an assignment statement.
BASIC "remembers" the values that have been assigned to variables using this type of statement.
This "remembering" process uses space in the memory to store the data.
The values of variables are discarded (and the space in memory used to store them is released) when
one of four conditions occur:
* A new line is typed into the program or an old line is deleted
* A CLEAR command is typed in
* A RUN command is typed in
* NEW is typed in
Another important fact is that if a variable is encountered in a formula before it is assigned a value,
it is automatically assigned the value zero. Zero is then substituted as the value of the variable in
the
particular formula. Try the example below:
PRINT Q;Q+2;Q*2
0 2 0
RESERVED WORDS
The words used as BASIC statements are "reserved" for this specific purpose. You cannot use these
words as variable names or inside of any variable name. For instance, "FEND" would be illegal
because "END" is a reserved word.
Table 206-1 is a list of the reserved words in BASIC.
Table 206-1. AIM 65 BASIC Reserved Words
ABS FN LIST PRINT SPC
AND FOR LOAD POS SQR
ASC FRE LOG READ STEP
ATN GET MID$ REM STOP
CHR$ GOSUB NEW RESTORE STR$
CLEAR GOTO NEXT RETURN TAB
CONT IF NOT RIGHT$ TAN
COS INPUT NULL RND THEN
DATA INT ON RUN TO
DEF LEFT$ OR SAVE USR
DIM LEN PEEK SGN VAL
END LET POKE SIN WAIT
EXP