Why this is not working?

Hi all,

I am using the ?: operator to check if a number wasn't entered in a textbox. If nothing was enetered, I want to default it to "0". The reason is because I need to convert the value to a numeric value that will be stored in a database. Below is the code I am using.

Code:

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string test =  this.rtxtProtqty.Text == null ? "0" : this.rtxtProtqty.Text;

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Thanks in advance.

Quote:

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Originally Posted by admdev

Hi all,

I am using the ?: operator to check if a number wasn't entered in a textbox. If nothing was enetered, I want to default it to "0". The reason is because I need to convert the value to a numeric value that will be stored in a database. Below is the code I am using.

Code:

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string test =  this.rtxtProtqty.Text == null ? "0" : this.rtxtProtqty.Text;

---

Thanks in advance.

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rtxtProtqty.Text never is gonna be null. You can check it by

Code:

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string test = (this.rtxtProtqty.Text.Trim().Length == 0) ? "0" : this.rtxtProtqty.Text;

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There is alreay method to cover both cases

Code:

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string test =  String::IsNullOrEmpty(this.rtxtProtqty.Text) ? "0" : this.rtxtProtqty.Text;

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You can also you the String.IsNullOrEmpty method

Code:

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string test = (String.IsNullOrEmpty(this.rtxtProtqty.Text.Trim()) ? "0" : this.rtxtProtqty.Text );

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EDIT : sorry for the double reply. Had the same idea at the same time as STLDude

Thanks guys!

It's working.

If you use a NumericUpDown control you will never have this problem

Or generally, you can set a mask if the control you are using does support it. For example, in case of DevExpress it is like this: this.txtNotificationLimitAfterDeal.Properties.Mask.EditMask = "#,#############0";

Quote:

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Originally Posted by STLDude

There is alreay method to cover both cases

Code:

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string test =  String::IsNullOrEmpty(this.rtxtProtqty.Text) ? "0" : this.rtxtProtqty.Text;

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Yes you can use this but
a) you need to have VS 2008 as the 2.0 framework doesn't have this method and
b) its totally useless. The TextProperty of a Textbox never is null. No case. If ther is nothing its string.Empty.
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edited :
point a) is not correct see following posts.

Quote:

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Originally Posted by JonnyPoet

Yes you can use this but
a) you need to have VS 2008 as the 2.0 framework doesn't have this method...

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Simply not true, here.

Quote:

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Originally Posted by JonnyPoet

its totally useless. The TextProperty of a Textbox never is null. No case. If ther is nothing its string.Empty.

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It's only 'totally useless' if you tie your application to only ever work the the TextBox.Text property. Any proper separation of frontend and backend would require the null check as well as the empty check.

Secondly, if null or empty are not valid inputs, then you should always use String.IsNullOrEmpty so if things do change in the future, you're still covered.

Quote:

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Originally Posted by STLDude

Simply not true, here.

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Sorry , my fault. But I did a quick try using it in a method and got an compilation error, so I thought its maybe up to 2008 as I have 2005 here on this machine. Now as you showed the reference I tried again and looked exactly what the errormessage told me . 'The namespacequalifier'::' is not allowed at this place.' Now I tried String.IsNullOrEmpty(...) and this works.
So this is in obviously included in framework 2.0 but you need to use String.IsNullOrEmpty(...) instead of String:: IsNullOrEmpty(...)

Sorry about ::, C++ came through too much, yes it should be .