How to set null value to int in c#?
C#.NetNullIntNullableC# Problem Overview
int value=0;
if (value == 0)
{
value = null;
}
How can I set value
to null
above?
Any help will be appreciated.
C# Solutions
Solution 1 - C#
In .Net, you cannot assign a null
value to an int
or any other struct. Instead, use a Nullable<int>
, or int?
for short:
int? value = 0;
if (value == 0)
{
value = null;
}
Further Reading
Solution 2 - C#
Additionally, you cannot use "null" as a value in a conditional assignment. e.g...
bool testvalue = false;
int? myint = (testvalue == true) ? 1234 : null;
FAILS with: Type of conditional expression cannot be determined because there is no implicit conversion between 'int' and '<null>'.
So, you have to cast the null as well... This works:
int? myint = (testvalue == true) ? 1234 : (int?)null;
UPDATE (Oct 2021):
As of C# 9.0 you can use "Target-Typed" conditional expresssions, and the example will now work as c# 9 can pre-determine the result type by evaluating the expression at compile-time.
Solution 3 - C#
You cannot set an int
to null
. Use a nullable int (int?
) instead:
int? value = null;
Solution 4 - C#
int does not allow null, use-
int? value = 0
or use
Nullable<int> value
Solution 5 - C#
public static int? Timesaday { get; set; } = null;
OR
public static Nullable<int> Timesaday { get; set; }
or
public static int? Timesaday = null;
or
public static int? Timesaday
or just
public static int? Timesaday { get; set; }
static void Main(string[] args)
{
Console.WriteLine(Timesaday == null);
//you also can check using
Console.WriteLine(Timesaday.HasValue);
Console.ReadKey();
}
The null keyword is a literal that represents a null reference, one that does not refer to any object. In programming, nullable types are a feature of the type system of some programming languages which allow the value to be set to the special value NULL instead of the usual possible values of the data type.
https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/null https://en.wikipedia.org/wiki/Null
Solution 6 - C#
Declare you integer variable as nullable
eg: int? variable=0; variable=null;
Solution 7 - C#
int ? index = null;
public int Index
{
get
{
if (index.HasValue) // Check for value
return index.Value; //Return value if index is not "null"
else return 777; // If value is "null" return 777 or any other value
}
set { index = value; }
}