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5.6.2.2 Evaluation to a simple data value

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Static semantics. The following types of expressions can be evaluated to produce a simple data value:

  • An expression classified as a value expression can be evaluated as a simple data value based on the following rules:

    • If the declared type of the expression is a type other than a specific class, Variant or Object, the declared type of the simple data value is that of the expression.

    • If the declared type of the expression is Variant or Object, the declared type of the simple data value is Variant.

    • If the declared type of the expression is a specific class:

      • If this class has a public default Property Get or function and this default member’s parameter list is compatible with an argument list containing 0 parameters, simple data value evaluation restarts as if this default member was the expression.

  • An expression classified as an unbound member, variable, property or function can be evaluated as a simple data value if it is both valid to evaluate the expression as a data value, and valid to evaluate an expression with the resulting classification and declared type as a simple data value.

    Runtime semantics. At runtime, the simple data value’s value and value type are determined based on the classification of the expression, as follows:

  • If the expression is a value expression:

    • If the expression’s value type is a type other than a specific class or Nothing, the simple data value’s value is that of the expression.

    • If the expression’s value type is a specific class:

      • If the source object has a public default Property Get or a public default function, and this default member’s parameter list is compatible with an argument list containing 0 parameters, the simple data value’s value is the result of evaluating this default member as a simple data value. 

      • Otherwise, if the source object does not have a public default Property Get or a public default function, runtime error 438 (Object doesn’t support this property or method) is raised.

    • If the expression’s value type is Nothing, runtime error 91 (Object variable or With block variable not set) is raised.

  • If the expression is classified as an unbound member, variable, property or function, the expression is first evaluated as a data value and then the resulting expression is reevaluated as a simple data value.