Option Strict Off

Question

 

Option Strict Off

Option Explicit On

how thes statments useful in when  creation of classes in vb.net
what does they mean

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adil

Answer 1

Option Strict -> http://msdn.microsoft.com/en-us/library/zcd4xwzs(VS.71).aspx

Option Explicit -> http://msdn.microsoft.com/en-us/library/y9341s4f(VS.80).aspx

Option Explicit should always be on, to catch any small typos in your code. Personally, I never have Option Strict on, and have yet to encounter a problem.

Wayne

Answer 2

they both should be on.

Answer 3

Option Strict Off allows late binding which drastically slows a program.  It also allows very sloppy programming.  If you need assistance and you post code that compiled for you with Option Strict Off, the squiggly lines will likely turn off quite a few of the responders on these forums.  For the cleanest,  most versatile and maintainable code set:

Option Explicit On
Option Strict On
Option Infer Off

Answer 4

webtubbs said:

Option Strict -> http://msdn.microsoft.com/en-us/library/zcd4xwzs(VS.71).aspx

Option Explicit -> http://msdn.microsoft.com/en-us/library/y9341s4f(VS.80).aspx

Option Explicit should always be on, to catch any small typos in your code. Personally, I never have Option Strict on, and have yet to encounter a problem.

Wayne

Hi ALL,

For completeness sake only.>>

OPTION INFER -> http://msdn.microsoft.com/en-us/library/bb384665.aspx


OPTION COMPARE -> http://msdn.microsoft.com/en-us/library/8t3khw5f(VS.71).aspx


Regards,

John

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For links to VB.Net tutorials see here.>> http://social.msdn.microsoft.com/Forums/en-US/vblanguage/thread/29f2179b-997b-4115-a96d-a0834853b835

Answer 5

Hi ALL,

With OPTION INFER ON this is okay.>>

For x = 1 To 10

Next

as x is INFERRED to be an INTEGER

otherwise it has to be.>>

For x As Integer = 1 To 10

Next

'or

Dim x As Integer

For x = 1 To 10

Next

Regards,

John

---

For links to VB.Net tutorials see here.>> http://social.msdn.microsoft.com/Forums/en-US/vblanguage/thread/29f2179b-997b-4115-a96d-a0834853b835

Answer 6

Hi ALL,

With OPTION EXPLICIT ON

you can not do this.>>

Number4 = 40


you have to state or be explicit about what you intend like this.>>

Dim Number4 As Integer = 40

 

which is the best thing to do,that is use the As INTEGER or whatever to remove any doubt ( ambiguity ) you may have.

'otherwise Number4 is an INTEGER with OPTION INFER ON & OPTION EXPLICIT OFF

'otherwise if you turn OPTION INFER OFF it is an OBJECT again.>>

Dim Number4 = 40


Regards,

John

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For links to VB.Net tutorials see here.>> http://social.msdn.microsoft.com/Forums/en-US/vblanguage/thread/29f2179b-997b-4115-a96d-a0834853b835

Answer 7

Hi ALL again,

OPTION STRICT OFF would allow you to do this.>>

TextBox1.Text = 1234

Me.Text = 456

Which is naughty really as the numbers 1234 and 456 above are not in STRING format.

OPTION STRICT ON forces you to convert to the right TYPE
for assigning one thing to another like this.>>

TextBox1.Text = 1234.ToString
'or
TextBox1.Text = (1234).ToString
'or
TextBox1.Text = Convert.ToString(1234)
'or
TextBox1.Text = CStr(1234)
'or simply
TextBox1.Text = "1234"


Regards,

John

---

For links to VB.Net tutorials see here.>> http://social.msdn.microsoft.com/Forums/en-US/vblanguage/thread/29f2179b-997b-4115-a96d-a0834853b835

Answer 8

Almost there,

To demonstrate a LATE BINDING error due to OPTION STRICT ON try this code then turn

Option Strict On

You do not need any controls added to a FORM to try this code.

To overcome such an error see the next post where the blue highlighted code is changed.


Regards,

John

Option Strict Off

Public Class Form1

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

'Set the FORM text to 1234567890123456890 >>

Me.Text = 1234567890123456890.ToString

'Maximize the FORM.>>

Me.WindowState = FormWindowState.Maximized

'Used to hold the current BUTTON.>>

Dim btn As Button

'Used for the BUTTON number.>>

Dim ButtonNumber As Integer = 0

For y As Integer = 1 To 5

For x = 1 To 10

'Add one to the BUTTON number.>>

ButtonNumber = ButtonNumber + 1

'Assign a NEW Button to btn.>>

btn = New Button

'Give the Button a SIZE.>>

btn.Size = New Size(40, 25)

'Assign the current number to the TEXT property of the button.>>

btn.Text = ButtonNumber.ToString

'Assign a NAME of Button1 ... to Button50 as appropriate.>>

btn.Name = "Button" & ButtonNumber.ToString

'Give it a LOCATION on the FORM.>>

btn.Location = New Point((x * 40) + 30, (y * 25) + 40)

'Add a HANDLER to HANDLE the CLICK event.>>

AddHandler btn.Click, AddressOf MyButtonsClickSub

'Add the Button to the FORM.>>

Me.Controls.Add(btn)

Next

Next

End Sub

Private Sub MyButtonsClickSub(ByVal sender As System.Object, ByVal e As System.EventArgs)

'Show which button was clicked on.>>

MessageBox.Show(sender.name)

End Sub

End Class

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For links to VB.Net tutorials see here.>> http://social.msdn.microsoft.com/Forums/en-US/vblanguage/thread/29f2179b-997b-4115-a96d-a0834853b835

Answer 9

Finally,

The above code corrected to avoid the LATE BINDING error with OPTION STRICT ON.

So I recommend the settings as stated earlier by forum user Mr John Wein.

Option Explicit On
Option Strict On
Option Infer Off

I will leave you to discover what OPTION COMPARE does. :-)


Regards,

John

Option Strict On

Public Class Form1

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

'Set the FORM text to 1234567890123456890 >>

Me.Text = 1234567890123456890.ToString

'Maximize the FORM.>>

Me.WindowState = FormWindowState.Maximized

'Used to hold the current BUTTON.>>

Dim btn As Button

'Used for the BUTTON number.>>

Dim ButtonNumber As Integer = 0

For y As Integer = 1 To 5

For x = 1 To 10

'Add one to the BUTTON number.>>

ButtonNumber = ButtonNumber + 1

'Assign a NEW Button to btn.>>

btn = New Button

'Give the Button a SIZE.>>

btn.Size = New Size(40, 25)

'Assign the current number to the TEXT property of the button.>>

btn.Text = ButtonNumber.ToString

'Assign a NAME of Button1 ... to Button50 as appropriate.>>

btn.Name = "Button" & ButtonNumber.ToString

'Give it a LOCATION on the FORM.>>

btn.Location = New Point((x * 40) + 30, (y * 25) + 40)

'Add a HANDLER to HANDLE the CLICK event.>>

AddHandler btn.Click, AddressOf MyButtonsClickSub

'Add the Button to the FORM.>>

Me.Controls.Add(btn)

Next

Next

End Sub

Private Sub MyButtonsClickSub(ByVal sender As System.Object, ByVal e As System.EventArgs)

'Define a button object.>>

Dim ButtonClicked As Button

'Convert the sender object to TYPE Button

'assigning the result to ButtonClicked.>>

ButtonClicked = CType(sender, Button)

'Show which button was clicked.>>

MessageBox.Show(ButtonClicked.Name)

End Sub

End Class

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For links to VB.Net tutorials see here.>> http://social.msdn.microsoft.com/Forums/en-US/vblanguage/thread/29f2179b-997b-4115-a96d-a0834853b835

Answer 10

Short note:

Code written that works with OPTION STRICT ON will usually ALWAYS work with
 OPTION STRICT OFF ( unless your code generates some other error ).


Code written that works with OPTION STRICT OFF will NOT ALWAYS work with OPTION STRICT ON.

Answer 11

 

Thanks John Anthony Oliver , i read your posts, its really very useful
Thanks for this help.

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adil

Answer 12

Hi Adil,

You're welcome.

See also.>>
http://social.msdn.microsoft.com/Forums/en-US/vblanguage/thread/ed44dd90-ab13-4f31-a69d-d471f7a27854/


Regards,

John

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For links to VB.Net tutorials see here.>> http://social.msdn.microsoft.com/Forums/en-US/vblanguage/thread/29f2179b-997b-4115-a96d-a0834853b835