CODEWITHSUNDEEP
c#
Brian Green
Brian Green

Reputation: 567

Are there edge cases for checking if a string is null?

I recently took ownership of some code from an author that is no longer with the company. Throughout the code I'm finding this line

if (string.Compare(string.Empty, textbox1.Text, true) == 0)

I'm not the most advanced C# programmer, but to me that seems functionally the same as

if (textbox1.Text == "")

Is there any edge case that the first line will catch that the second one won't?

Upvotes: 2

Views: 814

Answers (2)

dcastro
dcastro

Reputation: 68640

Actually, you should use String.IsNullOrEmpty(textbox1.Text) instead.

As pointed out in the comments, String.IsNullOrWhitespace is especially useful since you're working with GUI controls, which often may contain just whitespace, and not actually be an "empty" string.

Upvotes: 7

Habib
Habib

Reputation: 223217

It is comparing string ignoring case, but its a bad way of doing it. String.Equals has an overload for comparing strings with ignoring case.

To check if string consist of empty string, String.IsNullOrEmpty should be used, if you are using .Net framework 4.0 or higher and you want to consider space as empty string then you can use string.IsNullOrWhiteSpace.

If you only want to compare the value with empty string then textbox1.Text == "" or textbox1.Text == string.Empty is enough.

Upvotes: 6

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