In C#, the IsNullOrEmpty()
method can be used to check if a string is empty or null
. But if we want to check if a string is empty or just has whitespace, we can use the IsNullOrWhiteSpace()
method.
The IsNullOrWhiteSpace()
is used to indicate whether a specified string is empty, null
, or contains only whitespace.
string.IsNullOrWhiteSpace(str)
str
: The string we want to check if it’s empty, null
, or contains only whitespace.
The function returns True
if the string is actually empty, null
, or contains only whitespace. Otherwise, the function returns False
.
In the code below, we’ll demonstrate the use of the IsNullOrWhiteSpace()
method. We’ll create some strings with values and some with empty values. Then we’ll find out if they’re empty or not.
// create classclass WhiteSpaceChecker{// main methodstatic void Main(){// create stringsstring str1 = "Educative.io";string str2 = " ";string str3 = "";string str4 = " Edpresso ";// check if they contain whitespaces or emptybool a = string.IsNullOrWhiteSpace(str1);bool b = string.IsNullOrWhiteSpace(str2);bool c = string.IsNullOrWhiteSpace(str3);bool d = string.IsNullOrWhiteSpace(str4);// print out returne boolean valuesSystem.Console.WriteLine(a);System.Console.WriteLine(b);System.Console.WriteLine(c);System.Console.WriteLine(d);}}
Line 2,3: str2
and str3
contain whitespace and are empty.
Line 14,15: str2
and str3
are checked with the IsNullOrEmpty()
function and they return True
.