ARB ARB -4 years ago 174
C# Question

Replace string value with '0' when string is empty

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.

Answer Source

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())
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