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String::IsNullOrEmpty Method

Indicates whether the specified string is nullptr or an Empty string.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

public:
static bool IsNullOrEmpty(
	String^ value
)

Parameters

value
Type: System::String

The string to test.

Return Value

Type: System::Boolean
true if the value parameter is nullptr or an empty string (""); otherwise, false.

IsNullOrEmpty is a convenience method that enables you to simultaneously test whether a String is nullptr or its value is Empty. It is equivalent to the following code:

result = s == nullptr || s == String::Empty;

You can use the IsNullOrWhiteSpace method to test whether a string is nullptr, its value is String::Empty, or it consists only of white-space characters.

The following example examines three strings and determines whether each string has a value, is an empty string, or is nullptr.

using namespace System;
String^ Test( String^ s )
{
   if (String::IsNullOrEmpty(s))
      return "is null or empty";
   else 
      return String::Format( "(\"{0}\") is neither null nor empty", s );
}

int main()
{
   String^ s1 = "abcd";
   String^ s2 = "";
   String^ s3 = nullptr;
   Console::WriteLine( "String s1 {0}.", Test( s1 ) );
   Console::WriteLine( "String s2 {0}.", Test( s2 ) );
   Console::WriteLine( "String s3 {0}.", Test( s3 ) );
}
// The example displays the following output: 
//       String s1 ("abcd") is neither null nor empty.
//       String s2 is null or empty. 
//       String s3 is null or empty.

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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