Executes one block of statements out of many, depending on a test expression.
Select [ Case ] test_expression [ Tol tolerance ] Case expression_list [ statements ] ... [ Case Else [ else_statements ] ] End [ Select ]
- Necessary expression of an elementary data type.
- Optional floating-point constant specifies the tolerance for rounding errors in comparisons. See Tol Clause for more information.
Necessary in a Case clause. A comma-separated list of expressions to match against test_expression. The expression can take one of the following forms:
expression_1 To expression_2
Is comparison_op expression
The range form permits matching a range of values. The value of expression_1 must be less than or equal to expression_2.
The comparison form permits open-ended comparisons using any comparison operator (<, <=, >, >=, =, or <>).
The simple form is a specialized comparison form which tests for equality with test_expression.
- Optional. One or more statements following Case that execute if test_expression matches any clause in expression_list.
- Optional. One or more statements following Case Else that execute only if no clause in any expression_list in any Case matches test_expression.
- Completes the statement. Alternatively, you can use End Select.
If test_expression matches a Case expression_list clause, then control moves to the block of statements that follow it and continues until the next Case, Case Else, or End Select. Control then passes to the statement following End Select. If more than one match is possible, only the first matching Case gets executed.
The Case Else clause is used to introduce the else_statements, which get executed only when there are no matches between test_expression and any of the Case expression_list clauses. Although not a requirement, it is considered a good practice to include one to handle any unexpected values of test_expression. If there are no matching Case clauses and no Case Else, then control passes to the statement following End Select.