Instrucción If… Then… Else

Contenido

# If...Then...Else Statement

Defines one or more statement blocks that you only want to execute if a given condition or expression is True.

### Sintaxis:

      If condition Then
          statements
      [{ElseIf} condition Then
          statements]
      [Else
          statements]
      {EndIf|End If}

Instead of End If you can write EndIf.

If statements can be shortened to one line when using single statement blocks.

      If condition Then statement [Else statement]

### Parámetros:

The If...Then statement executes program blocks depending on given conditions. When LibreOffice Basic encounters an If statement, the condition is tested. If the condition is True, all subsequent statements up to the next Else or ElseIf statement are executed. If the condition is False, and an ElseIf statement follows, LibreOffice Basic tests the next expression and executes the following statements if the condition is True. If False, the program continues either with the next ElseIf or Else statement. Statements following Else are executed only if none of the previously tested conditions were True. After all conditions are evaluated, and the corresponding statements executed, the program continues with the statement following EndIf.

Es posible anidar varias instrucciones If...Then.

Las instrucciones Else y ElseIf son opcionales.

Se puede usar GoTo y GoSub para salir de un bloque If...Then, pero no para saltar dentro de una estructura If...Then.

### Ejemplo:

El ejemplo siguiente permite introducir una fecha de caducidad de un producto y determina si esta ya ha pasado.

    Sub ExampleIfThenDate
        Dim sInput As String
        Dim dInput As Date

      On Error Goto inputError
        sInput = InputBox("Enter the expiration date (YYYY-MM-DD)")
        dInput = DateValue(sInput)

        If dInput < Date() Then
            MsgBox "La fecha de caducidad ya ha pasado"
        ElseIf dInput > Date() Then
            MsgBox "La fecha de caducidad no ha pasado aún"
        Else
            MsgBox "La fecha de caducidad es hoy"
        End If

    inputError:
        If dInput = 0 Then MsgBox "Invalid input"
    End Sub

Temas relacionados

Select Case statement

Iif or Switch functions