Why do all three if statements get executed every time?

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I am working on windows forms. I have a log in form. I am using three If statements in the log in form. The code i have used in the log in form is as given below. However every time i enter the user name and password, all the three if statements get executed.
But i want only one If statement to get executed everytime. How do i rectify this.

What I have tried:

VB

Public Class WELCOME
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        If TextBox1.Text = "EMPLOYEE" And TextBox2.Text = "PASSWORD" Then
            Me.Hide()
            PROBLEMS.Show()
        End If

        If TextBox1.Text = "EMPLOYEE" And TextBox2.Text IsNot "PASSWORD" Then
            MessageBox.Show("Incorrect Password")
        End If

        If TextBox1.Text IsNot "EMPLOYEE" And TextBox2.Text = "PASSWORD" Then
            MessageBox.Show("Incorrect User Id")
        End If

    End Sub
End Class

Posted 21-Mar-16 20:48pm

Member 12247039

Updated 21-Mar-16 21:13pm

Michael_Davies

v2

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Comments

F. Xaver 22-Mar-16 3:41am

IsNot is comparing object references, not the Object it self.
I'm pretty sure you better go with '<>' operator

4 solutions

Solution 4

Use IF ELSE statement, it will resolve your issue, additionally you need to use ExitSub to exit from event

VB

If TextBox1.Text.toUpper() = "EMPLOYEE" And TextBox2.Text.toUpper() = "PASSWORD" Then
 Me.Hide()
 PROBLEMS.Show()

Else If (TextBox1.Text.toUpper() <> "EMPLOYEE") Then
MessageBox.Show("Incorrect Username")
Exit sub

ELSE If (TextBox2.Text.toUpper() <> "PASSWORD") Then
MessageBox.Show("Incorrect Password")
Exit sub
End If

hope it helps

Posted 21-Mar-16 21:13pm

koolprasad2003

Updated 22-Mar-16 0:10am

v2

Comments

Member 12247039 22-Mar-16 3:27am

Thank You. It does solve my purpose without using the Exit Sub.

Sascha Lefèvre 22-Mar-16 5:37am

if/if-else is not a loop! If you're looking for a word how to call it: statement

koolprasad2003 22-Mar-16 6:09am

Ooops ...Typo
Thanks for correction.

Solution 3

Read about elseif : If...Then...Else Statement (Visual Basic)[^]
http://www.dotnetperls.com/if-vbnet[^]

Posted 21-Mar-16 21:11pm

Mehdi Gholam

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Patrice T · Accepted Answer · 2016-03-21T21:09:00

Quote:
Why do all three if statements get executed every time?

That is what you requested in your code.
Try this:

VB

Public Class WELCOME
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

If TextBox1.Text = "EMPLOYEE" And TextBox2.Text = "PASSWORD" Then
	Me.Hide()
	PROBLEMS.Show()
	
ElseIf TextBox1.Text = "EMPLOYEE" And TextBox2.Text IsNot "PASSWORD" Then
	MessageBox.Show("Incorrect Password")

ElseIf TextBox1.Text IsNot "EMPLOYEE" And TextBox2.Text = "PASSWORD" Then
	MessageBox.Show("Incorrect User Id")
End If

End Sub
End Class

the use of ElseIf ensure that only one if will be executed, it don't ensure that your logic is correct.

Michael_Davies · Accepted Answer · 2016-03-21T21:10:00

The solution is to use Else or ElseIf.

VB

If TextBox1.Text = "EMPLOYEE" And TextBox2.Text = "PASSWORD" Then
Me.Hide()
PROBLEMS.Show()
ElseIf TextBox1.Text = "EMPLOYEE" And TextBox2.Text IsNot "PASSWORD" Then
MessageBox.Show("Incorrect Password")
ElseIf TextBox1.Text IsNot "EMPLOYEE" And TextBox2.Text = "PASSWORD" Then
MessageBox.Show("Incorrect User Id")
End If