Estructura de Selección en Visual Basic
COMP 215
Definición
• La estructura de selección la utilizamos cuando necesitamos programar el computador para que, dependiendo del cumplimiento o no de ciertas condiciones dentro del programa, se ejecuten o no instrucciones.
If Blocks
• If condition Then action1Else action2End If
Flowchart general
Is the condition true?
Execute action2 Execute action1
TN
ElseIf clauses
If condition1 Then action1ElseIf condition2 Then action2ElseIf condition3 Then action3Else action4End If
Ejemplo programación ElseIf ElseIf Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim gpa As Double Dim honors As String gpa = CDbl(TextBox1.Text) If gpa >= 3.9 Then honors = "summa cum laude..." ElseIf gpa >= 3.6 Then honors = "magna cum laude..." ElseIf gpa >= 3.3 Then honors = "cum laude..." ElseIf gpa >= 2.0 Then honors = "........." Else honors = "You don't graduated..." End If TextBox2.Text = gpa & " " & honors End SubEnd Class
Select Case Block
Select Case selector Case valueList 1 action1 Case valueList 2 action2 Case Else action of last resortEnd Select
Ejemplo programación Select CaseSelect CasePublic Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim gpa As Double Dim honors As String gpa = CDbl(TextBox1.Text) Select Case gpa Case Is >= 3.9 honors = "summa cum laude..." Case Is >=3.6 honors = "magna cum laude..." Case Is >= 3.3 honors = "cum laude..." Case Is >=2.0 honors = "........." Case Else honors = "You don't graduated..." End Select TextBox2.Text = gpa & " " & honors End SubEnd Class
Top Related