What's the difference between 'int?' and 'int' in C#?

Question

I am 90% sure I saw this answer on stackoverflow before, in fact I had never seen the \"int?\" syntax before seeing it here, but no matter how I search I can\'t find the pre

Answer 1

int belongs to System.ValueType and cannot have null as a value. When dealing with databases or other types where the elements can have a null value, it might be useful to check if the element is null. That is when int? comes into play. int? is a nullable type which can have values ranging from -2147483648 to 2147483648 and null.

Reference: https://msdn.microsoft.com/en-us/library/1t3y8s4s.aspx

Answer 2

you can use it when you expect a null value in your integer especially when you use CASTING ex:

x= (int)y;

if y = null then you will have an error. you have to use:

x = (int?)y;

Answer 3

int? is Nullable.

MSDN: Using Nullable Types (C# Programming Guide)

Answer 4

int? is the same thing as Nullable. It allows you to have "null" values in your int.

Answer 5

Int cannot accept null but if developer are using int? then you store null in int like int i = null; // not accept int? i = null; // its working mostly use for pagination in MVC Pagelist

Answer 6

the symbol ? after the int means that it can be nullable.

The ? symbol is usually used in situations whereby the variable can accept a null or an integer or alternatively, return an integer or null.

Hope the context of usage helps. In this way you are not restricted to solely dealing with integers.