VBC09333 — Variable required

Severity: Error · Family: VBC (static semantics / abstract syntax tree) · Source metadata: VBCompileErrorInfo

An expression that is not a variable is where a statement requires a variable: a value is to be assigned into it.

MS-VBA reports the same error: Variable required - can't assign to this expression.

This code is raised for the statements whose operands the specification says "MUST be classified as a variable" (MS-VBAL §5.6.1): MidStatementStaticSemantics and FileStatementStaticSemantics. It is raised as well for the target of a Let, Set, LSet or RSet statement, the control variable of a For or For Each loop and the target of a ReDim statement, which can't be a constant nor a function of the library (MS-VBAL §5.4.3.8, §5.4.3.9, §5.6.16.6, §5.4.3.3) - though the target of a Let statement may be a function of the library whose declared type is a class, Object or Variant (MS-VBAL §5.4.3.8) - and for an element of an Erase statement, which can't be a constant (MS-VBAL §5.4.3.4).

How it is raised

Situation	Example	Resolution
The target of a `Mid` statement is not a variable.	`Mid(Left, 1, 1) = "x"`	Assign into a variable that holds the string.
The target of a `Line Input #`, an `Input #` or a `Get` is not a variable.	`Line Input #1, "x"`	Read into a variable.
The expression is a constant.	`Input #1, Limit`, for `Const Limit = 10`	Read into a variable.
The target of an assignment is a constant.	`vbCrLf = 5`, `Limit = 5`, `VbDayOfWeek.vbSunday = 1`	Assign to a variable.
The target of an assignment is a function of the library - unless the statement is a `Let` and the function's declared type is a class, `Object` or `Variant`.	`Left$ = "x"`, `Set Left = Nothing`, `LSet Err = "x"`	Assign to a variable.
The control variable of a `For` or `For Each` loop is a constant.	`For vbSunday = 1 To 7`	Count with a variable.
The target of a `ReDim` statement, or an element of an `Erase` statement, is a constant.	`Erase vbCrLf`, `ReDim Limit(1)`	Erase or redimension an array variable.
The argument of `Len` or `LenB` is neither a `String` (or a `Variant`) nor a variable (RD-VBAL §6.1.2.11.1.22): a number, a `Boolean` or a date that is a literal, a constant, the result of an operator, a function or a property, or an object whose default member returns neither a `String` nor a `Variant`.	`Len(5)`, `Len(FnLong())`, `Len(Total)` for a `Total` object whose default member returns a `Long`	To count characters, convert it: `Len(CStr(5))`. To measure the size of its type, assign it to a variable and measure the variable.

Notes

Only an expression that is certainly not a variable is reported: a literal, the result of an operator, a constant - by its name, qualified by its project or its module, or qualified by the Enum of the library that declares it - and a function of the library. Which of the others - a member access, an index - is a variable depends on what it resolves to, and is not judged here. A name written with a type-declaration character is what its identifier names (MS-VBAL §5.6.10): after Dim Left$, Left$ = "x" is not reported. A function of the workspace assigned inside its own body is not reported, since there its name is its result, nor is a property. Nor is a function of the library whose declared type is a class, Object or Variant, as the target of a Let statement, since MS-VBAL §5.4.3.8 admits it: it assigns an object's default member (Err = 5), and has the statement raise error 450 when it runs for a Variant (Left = "x"). An element of an Erase statement may be a function (MS-VBAL §5.4.3.4), so only a constant is reported there.

Note

Not implemented. Some targets MS-VBAL §5.4.3.8 makes invalid are not reported yet: a function of the workspace or a Declared function assigned from outside its own body (F = 6 in another procedure), when its declared type is not a class, Object or Variant. It does not run: it fails in the host rather than raising a run-time error. Nor is an unqualified ReDim target that the declaration pass does not see - a name only the library or another module declares (ReDim vbCrLf(1), ReDim Left(1)) - since it becomes an implicit declaration of a local array; qualified (ReDim Strings.Left(1)), it is reported. See RD-VBAL §5.4.3.3 ReDim Statement.

Table of Contents

VBC09333 — Variable required

How it is raised

Notes

Note

See also