.NET built-in function that combines String.IsNullOrEmpty and String.IsNullOrWhiteSpace

Question

Is there a built-in function in .NET that combines both String.IsNullOrEmpty and String.IsNullorWhiteSpace?

I can easily write my own, but my question is why isn't there a String.IsNullOrEmptyOrWhiteSpace function?

Does the String.IsNullOrEmpty trim the string first? Perhaps a better question is, Does String.Empty qualify as white space?

Read the documentation about IsNullOrWhitespace. Goto MSDN before you ask here. — BenCr, Apr 15 '11 at 16:32

score 13 · Answer 1 · answered Apr 15 '11 at 16:28

13

why isn't there a String.IsNullOrEmptyOrWhiteSpace

That function is called string.IsNullOrWhiteSpace:

Indicates whether a specified string is null, empty, or consists only of white-space characters.

Shouldn’t that have been obvious?

answered Apr 15 '11 at 16:28

Konrad Rudolph

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It's not obvious - "empty" is the lack of whitespace – Matthew Layton Jul 31 '15 at 08:57
1

@series0ne I agree that it’s not obvious from the *name* alone, but from the documentation. And when you use a function you should obviously have read the documentation … – Konrad Rudolph Jul 31 '15 at 10:14

score 0 · Answer 2 · answered Apr 15 '11 at 16:29

0

Yes, the String.IsNullOrWhiteSpace method.

It checks if a string is null, empty, or contains only white space characters, so it includes what the String.IsNullOrEmpty method does.

answered Apr 15 '11 at 16:29

Guffa

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score 0 · Answer 3 · answered Apr 15 '11 at 16:34

0

String.IsNullOrWhiteSpace does check for null, Empty or WhiteSpace.

These methods do effectively Trim the string before doing the test so " " will return true.

answered Apr 15 '11 at 16:34

Mark Redman

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score 0 · Answer 4 · answered Feb 17 '12 at 19:22

Here is the decompiled method using dotPeek.

[TargetedPatchingOptOut("Performance critical to inline across NGen image boundaries")]
    public static bool IsNullOrEmpty(string value)
    {
      if (value != null)
        return value.Length == 0;
      else
        return true;
    }

    /// <summary>
    /// Indicates whether a specified string is null, empty, or consists only of white-space characters.
    /// </summary>
    /// 
    /// <returns>
    /// true if the <paramref name="value"/> parameter is null or <see cref="F:System.String.Empty"/>, or if <paramref name="value"/> consists exclusively of white-space characters.
    /// </returns>
    /// <param name="value">The string to test.</param>
    public static bool IsNullOrWhiteSpace(string value)
    {
      if (value == null)
        return true;
      for (int index = 0; index < value.Length; ++index)
      {
        if (!char.IsWhiteSpace(value[index]))
          return false;
      }
      return true;
    }

this thread has more answers http://stackoverflow.com/a/9334258/1060656 — aked, Feb 17 '13 at 13:03

.NET built-in function that combines String.IsNullOrEmpty and String.IsNullOrWhiteSpace

4 Answers4