Replace string value with '0' when string is empty

Question

I'm taking a value from a textbox and converting it to decimal. But, the textbox value could be empty. So, how could I handle empty strings from the textbox?

Unfortunately I have around 50 textboxes to deal with, so answers like 'check for null with IF condition' won't help me. My code will look ugly if I use all those IF conditions.

I have this

Convert.ToDecimal(txtSample.Text)

To handle nulls, I did this

Convert.ToDecimal(txtSample.Text = string.IsNullOrEmpty(txtSample.Text) ? "0" : txtSample.Text)

But, the above code is displaying '0' in the textbox. User does not want to see '0'. Another solution is to take text box value into a variable and convert the variable like below.

string variable = txtSample.Text;
Convert.ToDecimal(variable = string.IsNullOrEmpty(variable) ? "0" : variable)

But again, I do not want to define around 50 variables. I am looking for some piece of code that handles null values during conversion without adding the extra line of code.

What type of app is this? WPF? ASPNET? The reason I ask is becuase a WPF app has [Value Converters](http://wpftutorial.net/ValueConverters.html) that make this super easy. — Tacoman667, Jun 19 '14 at 14:42
+1'd the post to offset a spurious -1(?). Dunno why people still -1 posts without a reason... c'mon folks... — code4life, Jun 20 '14 at 21:42

score 17 · Accepted Answer · answered Jun 19 '14 at 14:39

17

But, the above code is displaying '0' in the textbox. User does not want to see '0'.

This is because your statement is assigning the new value to txtSample.Text (when you do txtSample.Text = ...). Just remove the assignment:

Convert.ToDecimal(string.IsNullOrEmpty(txtSample.Text) ? "0" : txtSample.Text)

To make things easier if you have many text fields to handle, you can define an extension method :

public static string ZeroIfEmpty(this string s)
{
    return string.IsNullOrEmpty(s) ? "0" : s;
}

And use it like this:

Convert.ToDecimal(txtSample.Text.ZeroIfEmpty())

answered Jun 19 '14 at 14:39

Thomas Levesque

286,951
70
623
758

lol..I am feeling like an idiot after reading your answer. haha. Why did I assign the value to the textbox in the first place? and when the problem was obvious why was I not thinking of removing the assignment? What the hell have I been thinking for 2 hours to fix this? haha. I think my programming part of brain was shut down and I was thinking with other parts of the brain. :) . Anyway, thanks mate. – ARB Jun 19 '14 at 14:50

score 2 · Answer 2 · edited Mar 22 '17 at 20:01

2

You could make a function to keep from copying the code all over the place.

decimal GetTextboxValue(string textboxText)
{
    return Convert.ToDecimal(string.IsNullOrEmpty(textboxText) ? "0" : textboxText);
}

and then use it like this:

GetTextboxValue(txtSample.Text);

edited Mar 22 '17 at 20:01

Raj Baral

661
6
19

answered Jun 19 '14 at 14:42

Becuzz

6,846
26
39

nice one mate. I ll do this. But I cannot mark it as answer beacuse I already did that to another answer. – ARB Jun 19 '14 at 14:58
1

Good answer. Replace the (variable) to (textboxText) on your answer. – Raj Baral Mar 22 '17 at 18:39

score 0 · Answer 3 · answered Jun 19 '14 at 14:48

You can create an extension method for the string as below

        public static decimal ToDecimal(this string strValue)
        {
            decimal d;
            if (decimal.TryParse(strValue, out d))
                return d;
            return 0;
        }

Then you can just txtSample.Text.ToDecimal() in every place.

Replace string value with '0' when string is empty

3 Answers3

Linked