5.4.3.4 Erase Statement

Note

This section describes the implementation of MS-VBAL §5.4.3.4 Erase Statement.

Syntax

AST node	Instruction kind(s)	Notes
KeywordStatementNode (`Token`: `Erase`)	`Simple`	See RD-VBAL §3.4.2 Simple Statements.

Static Semantics

The declared type of each erase-element must be an array or a Variant.

Runtime Semantics

Erase is ReDim's opposite: ReDim gives a resizable array its dimensions, and Erase takes them away again (RD-VBAL §5.4.3.3 ReDim Statement). What it does depends on which kind of array it was given, because a fixed-size array's bounds are part of its declaration and nothing at run time may change them.

Element	Effect
A resizable array	Set to an empty array of the same element type. The dimensions and the data are gone.
A `Variant` holding an array	The same. The variable keeps storing a `Variant`.
A fixed-size array	The dimensions stay. Every element is reset to its element type's default value.
Anything else	Runtime error 13, `Type mismatch`.

An Erase statement erases each element of its erase-list, in source order.

An erase-element that is not a simple name - a member access (obj.Items), an element (v(1)) - is an expression: the array is read from it, and a resizable array's emptied replacement is written back through it, as an assignment to it is. A fixed-size array is reset in place.

Implementation

Type or member	Role
`RDCore.Runtime.Semantics.Statements.ArrayStatementRuntimeSemantics`	Erases each element; see RD-VBAL §3.5.4 Execution.
VBResizableArrayValue, VBFixedSizeArrayValue	The two kinds of array the statement tells apart (RDCore.SDK).