type conversion

Basic does type conversions when the resulting value will "fit", but may report "TYPE MISMATCH" when presented with a conversion it thinks might not fit. It is best to match the type or do explicit conversions.

VALconverts its string argument to a number
STRconverts its numeric argument to a string


Variables of a specific type are declared by

     DIM variable AS type
Most types may be forced by appending the appropriate trailing character (called a type tag) to a variable, function or constant.
variant variables of undeclared type; may hold any type
string$"How now brown cow!!!!" mystring$
boolean true false
byte 0 to 255 only
date #1/1/1999# #26 Sep, 1944#
integer%123 &O77 (=63) &H0F (=15) &HFF (=255) myint%
long&123& 487289365 &O77& &HFF& &HFF0000 mylong&
single!4.8 3.14159! 1.e1 myreal!
double#4.8# .5d2# 1.d1 mydouble#
currency@3.52@ 3.1235@ 45238924.12@mymoney@
type a user defined type may be created by delarations bracketed by type and end type statements.

string variables may hold up to 32767 characters unless declared as string*n where "n" sets the limit on the number of characters in the string.

integer variables are in the range -32768 through 32767

long variables are in the range -2,147,483,648 through 2,147,483,647

single variables are for non-integer numbers using seven or fewer digits, while double variables are for non-integer numbers using 8 or more digits. On most systems single precision variable use the 4 byte IEEE single precision floating point format for numbers up to approximately 3.e38, while uses the corresponding 8 byte IEEE double precision format for 15 digit numbers up to approximately 1.e308.

currency numbers use 8 bytes to represent numbers with up to 4 decimal digits, with more than 14 digits before the decimal point.


An array is a collection of objects which are accessed by one or more indices.

     DIM variable( ilo TO ihi ) AS type
     DIM variable( ilo TO ihi, jlo TO jhi ) AS type
     DIM variable( ilo TO ihi, jlo TO jhi, klo TO khi ) AS type

If the lower index for any dimension is zero, it may be omitted.