Different between operator comparision and '.Equals(x)'

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

Hi All,
I would like to know what is the differnet between operator comparision
and '.Equals(x)'

Anthony
 
Anthony said:
I would like to know what is the differnet between operator comparision
and '.Equals(x)'
Click to expand...

The '==' operator for reference types is by default a reference
comparison. Only if the two values refer to the same object does it
return true, unless it has been overloaded. If '==' has been overloaded,
the version of '==' called is statically determined at compile time
based on the 'operator ==' definitions on the two types involved (one on
each side of the '==').

By default, '==' isn't defined for value types (structs), unless you
define one yourself.

The Equals method is virtual, and thus is selected by dynamic dispatch
at runtime. By default, it also performs a reference comparison, but it
may be overloaded. By the way, to ease the complications of checking for
null and avoiding calling Equals on a null reference, you can use
object.Equals(object,object) to call Equals and it can take care of
those details.

-- Barry
 
Thanks Barry, This is very helpful.

Barry Kelly said:
The '==' operator for reference types is by default a reference
comparison. Only if the two values refer to the same object does it
return true, unless it has been overloaded. If '==' has been overloaded,
the version of '==' called is statically determined at compile time
based on the 'operator ==' definitions on the two types involved (one on
each side of the '==').

By default, '==' isn't defined for value types (structs), unless you
define one yourself.

The Equals method is virtual, and thus is selected by dynamic dispatch
at runtime. By default, it also performs a reference comparison, but it
may be overloaded. By the way, to ease the complications of checking for
null and avoiding calling Equals on a null reference, you can use
object.Equals(object,object) to call Equals and it can take care of
those details.

-- Barry
Click to expand...
 
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