User`s manual

4-2
DEFINT
letter range
Variables beginning with any letter in the specified range will be stored and
treated as integers, unless a type declaration character is added to the
variable name. This lets you conserve memory, since integer values take up
less memory than other numeric types. And integer arithmetic is faster than
single or double precision arithmetic. However, a variable defined as integer
can only take on values between -32768 and +32767 inclusive.
Examples:
10 DEFINT A,I,N
After line 10, all variables beginning with A, I or N will be treated as
integers. For example, Al, AA, 13 and NN will be integer variables. However,
A1#, AA#, I3# would still be double precision variables, because of the type
declaration characters, which always over-ride DEF statements.
10 DEFINT I-N
Causes variables beginning with I, J, K, L, M or N to be treated as integer
variables.
DEFINT may be placed anywhere in a program, but it may change the
meaning of variable references without type declaration characters.
Therefore it is normally placed at the beginning of a program.
See
DEFSNG, DEFDBL,
and Chapter 1, "Variable Types".