overloading operator==

[volkan]

Hi,
I have a student class. In this class i overloaded ==,!= and equals so that
they will compare the studentids ( which is a member of the class ).
However i have a problem with null check.
public static bool operator !=(Student s1, Student s2)
{
...
how can i check if s1 or s2 is null or not in this overload.
if i do s1==null it goes recursive
if i typecast s1 down to object class, it seems not working
any ideas ?

 

[Jon Skeet [C# MVP]]

I have a student class. In this class i overloaded ==,!= and equals so that
they will compare the studentids ( which is a member of the class ).
However i have a problem with null check.
public static bool operator !=(Student s1, Student s2)
{
...
how can i check if s1 or s2 is null or not in this overload.
if i do s1==null it goes recursive
if i typecast s1 down to object class, it seems not working
any ideas ?

Casting s1 up to object should be fine. What problems are you having?
An alternative is to use object.ReferenceEquals().

 

[BlackWasp]

Have a look here.

http://www.blackwasp.co.uk/CSharpRelationalOverload.aspx

 

[BlackWasp]

D'oh, copy and paste failure!

http://msdn2.microsoft.com/en-us/library/ms173147(VS.80).aspx

 

[volkan]

thanx solved