What is 'long?' data type?
I am going over some code written by another developer and am not sure what long?
means:
protected string AccountToLogin(long? id)
{
string loginName = "";
if (id.HasValue)
{
try
{....
long
is the same as Int64
long data type
The ?
means it is nullable
A nullable type can represent the normal range of values for its underlying value type, plus an additional null value
Nullable Types
Nullable example:
int? num = null;
if (num.HasValue == true)
{
System.Console.WriteLine("num = " + num.Value);
}
else
{
System.Console.WriteLine("num = Null");
}
This allows you to actually check for a null
value instead of trying to assign an arbitrary value to something to check to see if something failed.
I actually wrote a blog post about this here.
long
is an Int64, the ?
makes it nullable.
long? is a 64-bit, nullable integer.
To clarify, nullable means it can be null or an integer number ( 0, 1, etc.).
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