Syntax

Select Case testexpression
[Case expressionlist
  [statement_block]]
[Case expressionlist
  [statement_block]]
  .
  .
[Case Else
  [statement_block]]
End Select

Description

Used to execute a block of the Basic Control Engine statements depending on the value of a given expression.

Comments

The Select Case statement has the following parts:

Part

Description

testexpression

Any numeric or string expression.

statement_block

Any group of the Basic Control Engine statements. If the testexpression matches any of the expressions contained in expressionlist, then this statement block will be executed.

expressionlist

A comma separated list of expressions to be compared against testexpression using any of the following syntaxes:

expression [,expression]...
expression to expression
is relational_operator expression

The resultant type of expression in expressionlist must be the same as that of testexpression.

Multiple expression ranges can be used within a single Case clause. For example:

 Case 1 to 10,12,15 Is > 40

Only the statement_block associated with the first matching expression will be executed. If no matching statement_block is found, then the statements following the Case Else will be executed.

A Select...End Select expression can also be represented with the If...Then expression. The use of the Select statement, however, may be more readable.

Example

This example uses the Select...Case statement to output the current operating system.

Sub Main()
  OpSystem% = Basic.OS
  Select Case OpSystem%
    Case 0,2
      s = "Microsoft Windows"
    Case 1
      s = "DOS"
    Case 3 to 8,12
      s = "UNIX"
    Case 10
      s = "IBM OS/2"
Case Else
      s = "Other"
  End Select
  MsgBox "This version of the Basic Control Engine is running on: " & s
End Sub

See Also

Choose (function); Switch (function); IIf (function); If...Then...Else (statement)

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