ZBasic Language Reference
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ZBasic Microcontrollers
If a string value is assigned that has fewer characters than a fixed-length string variable’s specified size,
the remaining characters will be filled with spaces. Secondly, if a string value is assigned having more
characters than a fixed-length string’s specified size, the excess characters will be discarded.
A fixed-length string is defined using the syntax:
{Public | Private | Dim} <name> as [New] String * <size-expr>
The keyword New is optional except in BasicX mode where it is required for compatibility reasons. When
defining a fixed-length string the <size-expr> should be a constant integral expression specifying the
number of bytes to allocate for the string’s characters.
Example
Dim msg as String * 15
This definition will create a string variable that always contains exactly 15 characters.
2.12 Variable Initialization
All statically allocated variables are initialized by the system immediately prior to Main() beginning
execution. For String types, this means that the bytes comprising the variable are set to represent an
empty string. For all other types, the constituent bytes are set to zero. Variables defined at the module
level and those defined using Static within a subroutine or a function are statically allocated and are,
therefore, initialized.
Dynamically allocated variables are not initialized by the system except for String types which are
initialized to represent an empty string. Variables defined using Dim within a subroutine or a function are
dynamically allocated.
When you define a variable you may provide an initial value by adding an equal sign and the desired
value (which must be a constant vaued expression) following the variable’s type. Initialization is not
supported for arrays, structures, Based or Alias variables nor for Program Memory or Persistent Memory
data items.
Examples
Dim count as Integer = 5
Dim str as String = "column"
2.13 Type Conversions
The ZBasic language is strongly typed meaning, for example, that it is not allowed to assign the value of a
constant, variable or parameter of one type to a variable or parameter of a different type. There are two
apparent exceptions to the strong-type regimen. The first exception is with respect to integral numeric
literals. An integral literal is considered to have a universal integral type (32-bit internally) so it can be
assigned to a parameter or variable of any integral type (Byte, Integer, UnsignedInteger, etc.).
Note that the presence of a plus sign or minus sign on a numeric literal does not change this
interpretation so it is allowable to assign the value –¹ to an unsigned variable type.
The second apparent exception to the strong typing rules occurs with the System Library routines. Many
of these routines will accept two or more data types for some of their parameters. It is as though several
different versions of the library routines exist, differing only in the types of the parameters that they
accept. This computer science concept is known as polymorphism.
The System Library routines include a set of functions for performing type conversions. The first set,
CBool(),CByte(), CInt(), CUInt(), CLng(), CULng(), CSng() and CStr() allows, with some
exceptions, conversion of a value of an arbitrary type to the target type. The second set, FixB(),
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